- I OF TEC NOV 3 1964 -19RARp1- ON THE LINEARIZED ATMOSPHEIC C0NT.IIBUTIONS TO REENTRY VEHICLE CEP F2ED MARVIN SHINNICK III S.B., Massachusetts Institute of Technology 1959 SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY June, 1964 Signature of Author Signature redacted Department of Aeronautics and Astronautics, June 1 9 64 Certified by Signature redacted Thesis Supervisor Signature redacted Accepted by Chairman, Departmental Graduate Committee ~ U 2 ON THE LINEARIZED ATMOSPHERIC CONTRIBUTIONS TO REENTRY VEHICLE CEP by Fred M. Shinnick III Submitted to the Department of Aeronautics and Astronautics on May 22, 1964 in partial fulfillment of the requirements for the degree of Master of Science. ABSTRACT The adjoint method of Bliss is explored as a means of computing the influence coefficients required for the computation of the atmospheric components of reentry vehicle CEP. It is found to be practical and straightforward when implemented on a modern digital computer, such as the IBM 7094. During the course of the investigation it was found that the statistical description of the atmospheric uncertainties affecting CEP is incomplete, and some of the possible effects of this incompleteness are detailed, while others are suggested. The author concludes that, by use of the adjoint method of Bliss, the development of detailed information concerning the reentry vehicle's response to statistical uncertainties in its environment is made sufficiently practical as to justify technically (but perhaps not financially) a more rigorous examination of the statistics of that environment from the relatively new (circa 1957) standpoint of interlevel correlations. Some inadequacies of the mathematical model used to describe the reentry vehicle are pointed out, together with some possible inadequacies of CEP itself as a design number, as possible areas of further investigation. iii ERRATA Page 10 line 2 replace 3 with 5 Page 17 line 3 omit ellipsis of five dots between "density" and "lat" Page 19 line 6 (from the bottom) Sentence beginning "A brief note . . ." should be replaced with: "A brief note on the effect of varying P (K) is in order." Page 32 line 13 replace "washed" with "averaged" Page 55 line 19 add to sentence ending in "show" the following phrase: ". . . since 50 ft/sec. is not greatly larger than the standard devistion pf winds at the altitude in question and since the winds extend over a comparitively small altitude region." Page 87 line 6 replace "addition" with "additional" Page 129 Reference 27 replace "statical" with "statistical". iv ACKNOWLEDGEMENTS The help, the courtesy, the generosity of many people made this thesis possible. are too many. I cannot thank them all by name here; they My first and deepest thanks go to those, not mentioned by name, who took time from their own lives to help me along. Many of these are employees of the AVCO Corporation's Research and Advanced Development Division, where I was privileged to work during part of the time this thesis was in preparation. Much of this work was supported by contractual work for the Ballistic Systems Division, Air Force Systems Comand. Among individuals, greatest thanks must go to Prof. W. E. VanderVelde, my thesis advisor, whose patience and help was beyond calculation, to Dr. F. W. Diederich, Vice-President, Engineering, AVCO/RAD, who suggested the topic, and Mr. Norman Sissenwine, of the Air Force Cambridge Research Laboratories, who gave freely of his knowledge of statistical climatology. Last, but very far from least, special thanks are due four people: Mr. J. DeNatale, Chief, Digital Prcgranming Section, AVCO/RAD, who sweated out the debugging of the programs with me, Miss J. Chapman, who put up with rough drafts beyond number, Mr. R. Rice, who was kind enough to look them over and suggest better English in places and D. A. Rogers who provided the inspiration for my attempting graduate work at all. Final responsibility for this thesis rests with myself, and my conclusions and recommendations are independent of any official views which the Defense Establishment may have on matters which are mentioned here. I vi TABLE OF CONTENTS Chapter No. Page No. 1 Introduction 1 2 Theoretical Discussion 5 3 The Computer Model 28 4 The Statistics of the Environment and Vehicle 46 5 Results, Conclusions and Recommendations 69 A Sample Computer Output from Adjoint Program 90 B Meteorological Data Used in Analysis Appendices 116 Figures 1 Probability of No-Kill vs. Kill Radius/CEP for Several Numbers of Missiles Arriving in 7 a Circular Normal Probability Distribution 2 Radius of Severe Damage for Underground Structures and Groundburst vs. Yield 3 Radius for Given Overpressure vs. Weapon Yield for 100,200 and 300 psi Overpressures 11 Sketch of the Normal Bivariate Probability Density Function 20 5 CEP for Unbiased Bivariate Normal Distribution 22 6 CD vs. M Used for the Study 30 7 Coordinate Uystemas Used W of Motion 35 Derive Equations 9 vii 8 The Matrix B 36 9 The Matrix C 37 10 Computational Scheme 38 11 Sketch of Wind-Trajectory Coordinate System 47 12a,b,c Estimate of Wind Bias Induced by Selective Loss of Radiosondes 13 Lines of Constant Range Over a Spherical, NonRotating Earth, from 300,000 ft Altitude to Altitude 14a,b Percentage of Density Influence Coefficient Above 32 km 72,73 15a,b Impact Mach Number vs. V & 75,76 16a,b Ratio of Density Influence Coefficient (all 77,78 bands) to Downrange Wind Influence Coefficient. (all bands), 17a,b Atmospheric CEP vs. V & 60,61,62 ' 70 80,81 Tables 1 Effects of Simplified Earth Model on Dispersion 29 2 Comparison of Dispersion Influence Coefficients Obtained by Adjoint Method With Those From Standard Trajectories 41 3 Altitudes fov.Commonly Used Pressure Levcls 57 4 Accuracy of U.S. Density M4easurements 58 5 Atmospheric CEP at r= -200 for V./CDA of 1000 82 6 Maximum Effect on Atmospheric CEP of Altering Certain Elements of the Covariance Matrix V 83 References 128 viii LIST OF SYMBOLS AND ABBREVIATIONS DEFINITION SYMBOL SEE: Eq. 2.3 A vector of dispersion influence coefficients a speed of sound, feet per second B matrix of partial derivatives shown in Fig. 8 Eq. 2.19 C matrix of partial derivatives shown in Fig. 9 Eq. 2.19 CD vehicle drag coefficient C q+CMA vehicle dynamic damping deriVative Chap. 1 circular error probable Chap. 1 D dispersion vector, feet vehicle aerodynamic drag, pounds Eq. 2.1 Eq. 3.2. E expectation of event C F vector of functions in Eq. 2.16 Eq. 3.2 G vector of functions in Eq. 2.17 Eq. 3.3 C EP GMT 2 Eq. 2.6 Greenwich Mean Time g 2 surface acceleration of gravity, feet per second h altitude, feet K constant used to calculate CEP m vehicle mass, slugs total number of perturbations, in Sec. 2.4 P J will occur probability that the event vector of quantities to be perturbed Eq. 2.9 p vector of perturbations in P Eq. 2.1 Fig. 5 U ix DEFINITION SYMBOL Q QI SEE: relative wind, i.e. velocity of R/V with respect to air, feet per second Eq. 3.2.3 "Quantity of Interest;" in this thesis, the downrange and crossrange components of miss distance in feet Eq. 2,24 radius of the earth, feet R R/V reentry vehicle S covariance matrix of impact points Eq. 2.9 S* orthogonalized matrix of impact points Eq. 2.15 machine time required to solve various parts of the problem Sec. 2.4 T, Tj, T t t time, seconds interval of integration, seconds u downrange component of wind, feet per second v crossrange component of wind, feet per second w vertical component of wind, feet per second V vehicle velocity relative to earth, feet per second W/CDA Sec. 3.6 Fig. 7 R/V ballistic performance parameter, pounds per square foot Eq. 3.1.1 dispersion influence coefficient due to wind, feet per foot per second Eq. 4.6 downrange distance, feet general random variable used to define expectation Eq. 3.1.4 Eq. 2.6 y crossitange distance, feet vector of perturbations in Y Eq. 3.1.5 Eq. 2.19 Y vector of state quantities weapon yield, equivalent tons of TNT Eq. 2.16 Sec. 2.1 flight path angle Fig. 7 angle between vehicle velocity and relative wind Fig. 7 reentry bearing angle Fig. 10 8W x 77 H x iYMBOL A DEFINITION SEE: angle relating vehicle velocity and relative wind vector of adjoint variables Fig. 7 Eq. 2.20 covariance Eq. 2.5 atmospheric density, slugs per cubic foot 0-' standard deviation Eq. 2.5 transformation matrix from S to S* Eq. 2.14 rotation angle defining g Eq. 2.13 Fig. 4 angle between the nominal trajectory plane and the perturbed trajectory plane Fig. 7 SUBSCRIPTS ETC. speed of sound Eq. 4.1 drag coefficient Eq. 4.1 E east wind Eq. 4.1 I number of density bands Eq. 4.6 influence coefficient bands Eq. 4.6 J number of wind bands Eq. 4,6 k target station Eq. 2.9 K number of target stations Eq. 2.9 N north wind Eq. 4.1 WX downrange wind Eq. 4.6 WY crossrange wind Eq. 4.7 x downrange Eq. 4.6 y crossrange Eq. 4.6 a CD ij xi DEFINITION SYMBOL pe.rtur 'ation in ( &( ) SEE: density ( ) derivative with respect to time ( )' derivative with respect to altitude () expectation of ( ) ( ) transpose of matrix or vector Eq. 2.6 CHAPTER 1 INTRODUCTION The defense of the United States in the nuclear age is largely based on the retaliatory power of the long range ballistic missile. It follows that an accurate analysis of such missiles is essential to national security, for the stakes, while simple to state, are beyond imagination and comprehension in any but a strictly numerical sense. If the deterrent succeeds, i.e. is not used, and an unnecessarily large part of the national defense budget is spent on it, the mistake will only be very expensive. If not enough is spent on it, and it is therefore too small, then the deterrent has an increased probability of failure, i.e. of being used. The question Herman Kahn uses to judge the resultant situation is: "Will the survivors envy the dead?" If the deterrent is larger than necessary and still fails, (for the probability of failure is never eliminated, only reduced) then there is a markedly increased chance that there will be no survivors to envy the dead. The stakes involved in the accurate estimation of ballistic missile system performance are awful. Technical performance receives a further dimension of importance if the possibility of arms control agreements is raised. As is pointed out by Kent 2 , improvements in system accuracy will be among the last 2 to come under arms control, and therefore will receive great emphasis after increasing weapon yields and numbers have been legislated out of existence as means of increasing system efftctivenes3s. How good is the state of the art of technical performance estimation? Jerome Weisner, former Presidential Science Advisor, writes the following rather illuminating passage : is typical of many in which the methods are simple and obvious, but is one which should be held in considerable suspicion because of the unreliability of the assumptions. In particular, estimates of exchange ratios are very sensitive to estimates of missile accuracy, a bit of information that is very hard to get and dangerous to trust completely, and one that is subject to change as missiles develop. This is not to imply that such calculations are not valuable, but rather that judgement and care should be applied when making and using them. This calculation*xV This thesis is an attempt to improve the confidence in which these estimates may be held safely. The measure of technical performance of a ballistic missile System is the probability thati it zill .kiAnits t&rgct complex,, The problem of computing this probability considered in its entirety is so complex as to defy description. In order to reduce the problem to analyzable size, it usually is cut along the physical joints of the system, e.g. the launch vehicle, the reentry vehicle, the defense system, etc., and the separated parts studied in a relatively independent fashion0 This thesis is concerned with one of the numbers used to obtain this probability, the CEP or circular error probable. CEP is defined as the radius of a circle, centered on a desired target point, within which the reentry vehicle's warhead has a probability of A simple CEP weapons allocation problem see 2.3. - of n 3 The problem of determining CEP is capable, in part, of linearization in that many of the causes of reentry vehicle dispersion may be analyzed on the basis of linearized equations with their attendant virtue of superposition. Those to be considered here are the effects of the reentry process, specifically the variations in the atmosphere over the target, i.e. the atmospheric density, the speed of sound, the winds; each a function of altitude, and a vehicle parameter, the drag coefficient, a function of Mach number. It is the decrease in computation time resulting from linearization which is the center of interest of this paper. In principle, a machine time speedup of at least a factor of 4 is likely; 10 is possible*, This is not to say that nonlinear components are unimportant. To mention briefly just one example, Murphy has described a species of nonlinearity in the aerodynamic damping coefficient Cmq+Cmd which can, in a reentry situation, generate a divergent angle of attack oscillation. This, in turn, will produce an increase in CD large enough to drive the effect of the resultant additional aerodynamic acceleration on impact point completely out of the linear range. However, the problems associated with computing such nonlinear effects are such that no appreciable speedup seems possible over the parametric or the Monte Carlo approaches of simply running many trajectories to discover what the influence on impact point of the nonlnear components is. A second area of concern emerged in the course of investigation, * As events turned out, a speedup of almost a factor of 20 was demonstrated as possible; the actual benefit is limited by the adequacy of statistical data to about 10. '4 The derivation of the model produces a requirement for certain statistical parameters defining what is known about the vehicle and its environment. Frequently, estimates of these parameters did not exist, and the question arises: How important are these parameters and what is the cost of neglecting them? This question is answered in part by this thesis. The other contributions of the reentry process to the technical performance of the missile system are the reentry system reliability and the airburst fuzing altitude error. These will not be discussed beyond this introduction because, in the case of the reliability, the errors required to induce catastrophic failure are such as to surpass the limitations of linearity, or, in the case of the airburst fuzing altitude error, the the current thinking with regard to fuzing systems is classified, and therefore the pertinent influence functions cannot be investigated here. Once these functions are determined, they may be manipulated by techniques analogous to those developed here. It should be noted that, in the case of airburst fuzing, there is a definite relationship between detonation altitude and detonation location. Obviously, an early detonation will be both high and short. Further, the importance of detonating at the altitude for maximum damage is such that, for airburst fuzing, the accuracy with which CEP need be determined may become less, since the airburst fuzing altitude error may become an important contributor to the determination of the kill probability, For an unclassified discussion of the importance of accurate determination of airburst altitude, Glasstone5 is recommended. For the remainder of this thesis, groundburst will be assumed in order to avoid 5 the problem. This also implies that a hard target is under attack, which in turn increases the stringency of the CEP requirements, 6 CHAPTER 2 THEORETICAL DISCUSSION 2.1 Order of Magnitude of CEP From Weapons Effects The sizes of CEP which are important may be obtained by considering first the probability of escaping kill given the size of CEP relative to the kill radius and then estimating the kill radius from studies of weapons effects. The circular normal probability distribution provides the worst requirement on CEP of any bivariate normal distribution, i.e. for any given kill probability, the ratio of CEP to kill radius is highest for this distribution. Therefore, this distribution will be assumed for the remainder of this section because it will result in a conservative (i.e. small) size for the minimum CEP of interest. Using the tables of Rosenthal and Rodder ility of no kill as a function of kill radius 6 we may show the probab- / CEP for several numbers of missiles fired at the target (Figure 1), From this figure, it may be seen that the advantage of reducing CEP relative to kill radius is not pronounced for weapons systems for which kill radius / CEP is much over two. This number will be considered the minimum CEP of interest. On the other hand, if kill radius / CEP is much less than 0.7, an acceptable kill probability produces unacceptable requirements on the number of reentry vehicles fired. This defines the maximum CEP of interest* 43 775 LA N ! 11 1 Ui 4-E1 if~4' I- T-1 I1 Hl 1IIII~ If0 -I Io rj t\l I t I 'i4~ I I I I I' P1 0 C'; 8 Two additional assumptions used in the preparation of Figure 1 should be noted: First, the probability of kill follows the "cookie cutter" hypothesis, i.e. the probability of survival inside the kill radius is zero; outside it is one. Second, if more than one reentry vehicle is fired at a given target, the attacking R/V's are statisti- cally independent. This point will be discussed further in the next section. To give even a rough estimate of kill radius requires three specifications: weapon yield, burst altitude and the kill criterion. A cursory survey of current unclassified estimates of US weapon yields suggests a range from 600 kilotons for Minuteman to ten megatons for Titan II, with a possible escalation of the latter to 35 megatons Secretary of Defense MacNamara7 indicates that there is good reason for going to many weapons of comparitively low yield which would tend to indicate that 35 megatons is probably an upper limit. The data of Reference 7 are used to provide bench marks for the following with the warning that they should not be trusted very far. Minuteman estimates in these sources range from 600 kilotons to one megaton, for example. The burst altitude is fixed by the assumption of groundburst; further it is quite arbitrarily restricted to sea-level. Kill criteria based on blast effects can be defined in two ways, by assuming the damaging effect to be related first to crater dimensions, and second to the maximum distance from ground zero at which a given overpressure occurs. Glasstone 5 , on page 300, suggests 1.25 crater radii as appropriate for hard underground structures. Within that radius, structural collapse is likely. The resultant kill radii are plotted against yield for rock and earth in Figure 2. Figure 3 gives, for the 2I~vrrF" I1II1 ~ '1 V.I2.{2t~4 4 l0~ J '3- 4 7+77 EJIJIL 1~. 8~-. 7- t T a L4LtA~ I U kL~4~7~4~J7fl - - t4 4h~ga 4 .~ 4 .4 t;4l -. 4 T5T, ' I - -4----- 1 IV 1 !Itt IL 4" I 8 J r LIl - - 1 !4I t~7l7-r- 4-t t I-i tITqT7 qWIp -. 7 2.5. ~ 17"'~ U.T lit t 1.5. j __j 1~ 1 '1 7 1titttjt1 4p AL V4 5 - 1 8 i 91 ( 4 -T- 1.5 Li ÷I 1' tt 2 2.5 iIB TI -7 -74- A.. .A. 10 same yields, maximum overpressure radii for three overpressures of common interest.* The assumptions behind the data of Reference 3 are largely unstated. Owing to the extremely rough cut in which we are interested in this section, no effort has been made to track these assumptions down. Putting these considerations together, we may reach the following conclusions: 1. The order of magnitude of CEP which is of interest to the ballistic missile systems analyst is from a few hundreds to a few thousands of feet. 2, Missile accuracy is a good place to attack the problem of increasing kill probability since kill radius / CEP is, to first order, the parameter of interest, and kill radius is weakly dependent on yield. (Roughly proportional to yl/3). 3.The above conclusion is relaxed slightly owing to the possibility that yield is not proportional to R/V weight. In fact, Kent2 suggests that yield scales as the )4!/3 power of weapon weight; therefore, if one assumes that R/V weight is proportional to weapon weight, yield will scale as the 4/3 power of R/V weight. This assumption will be used here. 2.2 Targeting Considerations CEP must not be considered simply as a design number, constant for a given reentry configuration. The purpose for which CEP is to be used, the target complex, the targeting philosophy and the deployment philos- ophy all can have an effect on how CEP is computed and on what the Although qverpressures of greater than 300 psi can be designed against, Weisner indicates that it is not practical. - II.- K 0-4 - 7+ ~~:t':t 4~~~ -4 - I 7__ 1 1 F' t 4-1 4-- 2- - . 2 7______ _____ 11 t I 2.5 1.1 2 I4 4.I t I +t1_ 1. 15 2 I4 I 1 ' .771 12 final value is. What will CEP be needed for? The following brief list is intended to be suggestive, not comprehensive. (1) Weapons allocation: The fundamental question here is: "How many reentry vehicles are needed to destroy this target with an adequate probability of success?" (2) Systems procurement: "How many reentry vehicles should be bought in all?" (3) Maintainance cycle determination: Owing to seasonal changes in the atmosphere, the CEP required for weapons allocation will fluctuate. As a result, the total allocation of reentry vehicles also may fluctuate, By taking advantage of this fact, one can time the down periods of missiles so that more are down for maintenance during periods when the atmospheric variability is small, and fewer missiles are needed4 This reduces the number of reserve missiles required to cover for the ones which are down. So we ask: "How does overall CEP vary with season?" (4) Systems design: "Given a preliminary shape, how big should it be for minimum system cost?" Figure 1 indicates that the larger the ratio of kill radius to CEP, the fewer reentry vehicles need be fired at a given target. For a given W/CDA and CD vs. Mach number, there are two tradeoffs: For a larger vehicle (up to the maximum size allowed by the booster) a larger and therefore higher yield and kill radius warhead may be accomodated. This, however, limits one to the immediate vicinity of the minimum energy combination of reentry velocity and flight path angle for a given ne. By moving , to a higher velocity and steeper reentry angle for the same range, (a "lofted" trajectory) the atmos- pheric contributions to CEP can be reduced. (The guidance error, however, may increase as Wheelon1 2 suggests.) This lofting implies a reduction in available weight and therefore in available yield6 It also 13 implies that less yield is required. Thus, the optimal size of the reentry vehicle (assuming booster thrust allows a choice) is not immediately obvious. Further, considerations of guidance system design and of attitude control system designll will be affected by CEP. How much weight is allocated to making the vehicle more accurate and how much is allocated to making the warhead bigger is the question to be asked. The nature of the sample over which the statistics are to be taken is different for each of the above uses; therefore CEP may be expected to be different. It should be noted that factors outside the scope of this study may minimize the effect of any of the above, e.g. the costs associated with providing a variable maintenance cycle could outweigh the savings from not needing as many reserve vehicles. The question of target com- plex enters owing to the fact that various types of targets may have a tendency to cluster either in given geographical locations or in given sorts of geographical locations. (Industrial sites near raw materials, command sites near government centers or buried in mountains, etc.) This in turn affects the input statistics in a manner which may be different from a purely random selection of targets. Therefore, it may be possible to predict a priori what the effect of the inclusion or exclusion of a given class of targets may be for the overall system procurement CEP. The targeting philosophy enters for many reasons. A few might be: (1) How are targets assigned to launch vehicles? If this assignment is random over the particular ensemble to be evaluated, then the bearing angle becomes random, with effects upon the statistics required which are discussed in Section 4.1, The advantages of retargeting on a random 14 basis are of a security nature: the enemy, not knowing or being able to predict which sites apply to his most critical targets, must attack them all; further, he will have to build a more elaborate defensive capability. because he will not know from which direction his threat will come. On the other hand, this procedure may select a set of bearing angles too close together or too far apart for optimum saturation of the enemy defense installation, and may limit performance in some cases. (2) How often is targeting changed? The fewer times retargeting is performed, the less likely it is that a mean target atmosphere will match the atmosphere on which targeting was predicated, thereby introducing a known bias which, in turn, affects CEP unfavorably. On the other hand, the more frequently the guidance system is readjusted, the less reliable the system becomes, owing to human error. A tradeoff analysis will be required in the design of the targeting procedure to maximize system performance. (3) How many R/V's arrive on target?* Curiously enough, the way in which CEP is calculated is affected by this number. There are two kinds of uncertainties which must be dealt with: those which .affect each R/V equally, and those which are random from R/V to R/V. An example of the first kind of error might be the target location. We think the target is at point A. In fact,.owing to imperfect geodesy, mapmaking, etc., there is an uncertainty as to where the target It is desireable at this time to note the'fact that the target considered is undefended. This simplifies the problem of defining the phrase "arrive on target," in that this event is defined in terms of two independent probabilities, the missile accuracy and the missile reliability relative to catastrophic failure for the undefended target. The defended target makes this a less simple problem0 * 15 really is. If we aim at point A with a perfect missile, and hit it, there is only a probability that the target is there. Further, if many shots are fired at point A with perfect missiles, and hit it, that probability is not changed, which, assuming the "'cookie cutter" kill probability description, means that the kill probability is not improved. This error has the nature of a random bias: it does not change from one sample to the next, but it is known only in a statistical sense. When dealing with this sort of uncertainty, one must spread one's shots to increase the probability of kill. The second kind of error is exemplified by the guidance system errors. Each R/V's reentry conditions represent a sample from the set of possible guidance responses to the launch environment. Here, if one fires at point A, one probably will miss in a random fashion, and the probability of kill will be improved when one fires more than once, even if the cookie cutter kill model is used. Since the aim point may be changed relative to the target in a random fashion, the relative sizes of the two sorts of error is subject to a degree of control, and the optimum ratio is not immediately obvious. To conclude this section, it is desireable to repeat what was written at the beginning: CEP must not be considered simply as a design number, constant for a given reentry configuration. A few of the considerations required before an evaluation can be made realistically have been mentioned; no attempt to be exhaustive or authoritative has been made; neither was an attempt made to check against current targeting philosophy. This section is included simply to emphasize the true nature of CEP: a design number, yes; but a design number which relates the system's hardware both to its software (i.e. its employment doctrine) and to specific environment; it cannot be rationally evaluated without examining both of these things in detail. 2.3 Basic Probability The sources of impact location error (or dispersion) which may be linearized are primarily of a continuous nature, such as perturbations the atmospheric density about its mean value. These perturbations are a function of altitude, as is the density itself. For a given trajectory, these linear components may be written as a vector equation impact c Dk (2.1) reentry Dk is a column vector of two components, the downrange and crossrange components of the vector from the aim point to the impact point. P is a column vector of six components; the variables which are to be perturbed. Five of these are explicit functions of altitude: the atmospheric density, speed of sound, and the three components of wind; downrange, crossrange and vertical. The sixth, the vehicle's drag coefficient, is an implicit function of altitude athrough its dependence on Mach number. The perturbations themselves are denoted by p. The partial derivative 4 is a 2x6 matrix of altitude dependent functions, and the index k (k a 1, .. , K) refers to a particular nominal trajectory. The convention that the partial derivative of a scalar with respect to a column vector is a row vector should be recalled. Statistical data on the Pk generally are not available as continuous functions of their independent variable, but as discrete 17 functions over finite bands of the independent variable. Typically, the sort of statement one may find is (using density as an example), "The standard deviation of density . . at 4 kilometers is 0" This value will be assumed in this thesis to be valid for all altitudes above the given altitude & below the next higher altitude at which a value is given. One may recognize this fact by redefining P K as the perturbations of the six variables, band by band, i.e., Plk is the density perturbation from zero km. to 2 km., P2 k from 2kmo to 4 km., etc.; pik is the CD perturbation from zero to .5 Mach, pi+ Ik from -5 to 1.1 Mach, etc. Now PK is a column vector of M components where M is the sum of the number of bands used to approximate each of the six components of the old perturbation vector. Equation 2.1 becomes = (2.2) As where A range p(2-3) The range is the size of one band of one independent variable. The assumption is now made that each of the variables making up the vector PK is random, with mean - ) (2.4) I4~ T6 L MO -ae -(25) . and with covariance matrix 18 where superscript T indicates the transpose; the bar superscript indicates the expectation: L where .; PCXdis the probability that X (2.6) Xe PL;<j is the value )( takes. If x is continuous /a) .'(0(2.7) where (2.8) Equation 2.4 simply implies a perfect targeting process, i.e., one in which the mean impact point is the aim point. This does not exclude the unknown biases which were discussed in section 1.2; only the known biases are eliminated by this assumption. The further assumption will be made that Dk is a random variable with a normal bivariate probability distribution function. be exactly true if each of the components of p k This will is normally distribu- ted; it will be approximately true (by virtue of the Central Limit Theorem) if none of the non-Gaussian components of Pk is of over- whelming importance. This is an exceedingly imprecise statement of the circumstances in which the central limit theorem is valid, however, Parzenl5, indicates that cases where the random variables are dependent are not yet completely analyzed. Therefore, the precise limits on the validity of this assumption should be investigated further. 19 The computation of CEP is, with these assumptions, a straightforward process. K L where PL4 is the probability that the kth target station will be se- lected. The bar indicates the expectation of the quantity beneath. Inserting the definition of Dk, we obtain Sz (2.10) by making use of the fundamental matrix identity of transposes Recalling that the expectation of a sum is the sum of the expectations of the terms, and that the expectation of a constant times a random variable is that constant times the expectation of the :random variable, 2.10 is simplified to Is P A 1Q F A (2.12) All the quantities in Equation 1.12 may be evaluated in principle, although it is not appropriate to discuss P[Ehere. The P[A]fall out- side the area of this paper as they are based on highly classified intelligence information; for our purposes, a single station will be investigated, thereby making the point moot. reason for error is in order. A brief note on the The word "station" implies not only a location, e.g., a hard command post, but a time, e.g., winter, Neither of these factors is distributed on an equi-likely basis among its possibilities, the first because one target simply is more important than another and the second because, for a variety of 20 reasons, war is not equally likely at all times. The matrix S is the covariance matrix for two normally distributed, correlated random variables. This may be visualized as the hill" of the bivariate normal probability distribution being skewed through an angle : Figure 4 By rotating the coordinate frame through p become uncorrelated. , the variables For the bivariate case, this process may be written (2.13) Z/U2 (2,14) s4 C)S C - I 0 Q (2-15) where S* is the desired uncorrelated matrix. Having the principal axes of the probability ellipse and their n rrn orientation, one then locates the aim point in the 0 max and 7 'n coordinate system and applies to Reference 6 for the CEP. If there 21 is no determinate bias (as is assumed here) the CEP may be read immediately from Figure 5. for 0 / O~ If a quick approximation is desired, <-.- 5 the approximation CEP is valid to within 2.3%. : 0,589 x (Qemax+ Tmin) It must be recalled, however, that, owing to the scaling laws described before, this represents a 7.06% error in yield required, and a warhead weight error of 5.25%. This strong dependence on CEP accuracy of design conditions will be emphasized in the comparisons to follow. The next section describes the calcu- lation of A;. 2.4 The Calculation of the Ak We may write the basic non linear equations of motion in brief as a vector equation c F (Y, P) (2.1:3) in the state vector, Y, the vector P of quantities to be perturbed, Since we are concerned with and the independent variable, time. fairly steep reentries of ballistic vehicles altitude will be monotonic with time and may be used as the independent variable by dividing 2.1 by the equation defining (2.17) Equations 2.16 - 2.19 are defined in detail in Chapter 3. To do so here would becloud the issue, which is the development of the adjoint equations to follow. This division results in a new set of equations in which Y is reduced by one. (2.18) A '4 I I I L .4 1144- 7V7' I' i1'1 '''~ t$ t{14fi'4t{{jiI}I ~ 777t - + -- r~rrr-rr~r~rr~r~r 4+f~rTTr~~r7 8 1 t 4 4~~ + I r t 4' t *v tt 4--+ 4 14 t 4tI T1 4T_ 1 .4 t H T I tlit It 11+ tT T~dnrtft~it~tttt'itttII 1 I+I 1 44 { T rf 'r{ I''' 1114 'I~t'1-r'n~tIFV*t 4 II i rt 4-4 -I :I -4- r1iT1fI 4 -i I 4 +II l + 4' 1 + 4 1 23 In principle these five non-linear equations (one for each of , X the five state variables V, x, y, would be solved for one perturbation after another, a nominal impact point subtracted from each of the perturbed ones, and the results collected into the m x 2 influence coefficient matrix defined before as Ak' (The sub- script k, which refers to trajectories, will be omitted in this section to avoid confusion with the components of the vector p.) The requirement on the computer to do this is approximately KT (Z +#1)minutes for m perturbations, assuming m is large so that program loading time is small compared to running time, The m/2 arises because one may be clever and not run the perturbed trajectory above the point where the perturbation exists. K is the number of nominal trajectories to be investigated and T is the time required to run one of these trajectories from reentry, On a 7094, if all the trajectories are stacked on the machine as one job to minimize the program loading time, this line of attack requires about ten minutes for 100 trajectories, and results in insufficiently accurate answers, since taking the difference between two nearly equal numbers removes many significant figures from the answer. Some improvement may be obtained by making explicit use of the assumed property of linearity. If we take the collection of partial derivatives represented by: 13 = y ,c P 1 24 we may write the linearized perturbation equations based on Eq. 2.18 in matrix form as: (2.19) Here B and C are 5x5 and 5x6 matrices, respectively, of altitude varying quantities. The lower case quantities y', y and p are the perturbations of the corresponding upper case quantities, and is not computed because h is not a random variable in this problem, + T ) where TJ 2 is the new time required to compute the nominal trajectory ( which will The computing time required has now become K(T is the be increased owing to increased output requirements,) and T* 2 time required to solve Eqs. 2.19 from reentry to the ground. This approach eliminates the loss of significant figures by dealing directly with the perturbations. Therefore, this method represents an improvement. By taking a further step, one may make great savings in time, 16 which is the however, and it is this step, first described by Bliss key to this section. Closely related to Equation 2.19 is a set of equations ' A = 6 _ called the adjoint equations. The adjoint functions, to be influence functions upon the -A(2.20) , will be shown 'quantity of interest' of the state variables Y, i.e. the value of 'A at a given altitude can be made to represent the change in the quantity of interest resulting from a unit perturbation in the state variables Y at the altitude in question. To show this, first premultiply Eq. 2.19 by 9T and 2.20 by yT and add: -rT 17- 13T(2,,21) wx- 25 By making repeated use of Eq. 2.11, this becomes which may be integrated from h (2.22) A- Cf_ ( ;\T y), to h 2 > hi to obtain f 2t GL& (2.23) Z If we neglect the integral term by assuming no perturbations p, we may obtain the effect of a change in the state variables at h 2 on the quantity of interest at h by writing ~~)) ~() L 7c(QL) Comparison of Eq. 2.24 with Eq. 2.23 shows that that the proper initial conditions for ' and therefore, will be simply the partial derivatives of the quantity of interest with respect to the state variables Y at the altitude of interest. For the dispersion problem the altitude of interest is h =0, and the quantities of interest are two of the state variables, yl, and y5 , the down and cross range perturbations of the trajectory. Because of this fact, the initial conditions on \ may be written by inspection; they are: 0 0 [= 0 0 0 0 1 0 10 1- (2.25) Thus, if one wished, one could obtain the perturbations owing to small changes in reentry conditions by running a nominal trajectory from reentry to the ground, to obtain the altitude dependent matrix B, and then solving Equations 2.20 from the ground back up, using the initial conditions 2.25. The product of at reentry and the I 26 'perturbations in state conditions at reentry would be the desired dispersions. The problem of perturbations in the environment, ratper than of state conditions directly is only slightly more complex, and is solved by using the integral term in Eq. 2.23. Rewriting Eq. 2.24, one obtains 7 _(2.26)C)-c L if one assumes no perturbations in reentry conditions (i.e. state variables), Recalling that the p are constant perturbations in environmental variables, such as CD and (0, over relatively small altitude bands, hl to h2 , we may rewrite Eq. 2.23 as: j ~J~O~L (2,27) where all terms on the right hand side except the third are zero. C a) (2.28) Another way of seeing what has been done here is to recall that and therefore, that Eq. 2.28 could be written Now, to obtain the -p ~pJ~Cd f( 2 ,2 9 ) ~y desired, simply obtain B and C histories from a solution of the nominal trajectory, as was done before when B was all that was needed; solve the adjoint equations exactly as before, using the same initial conditions 2.25 (QI has not changed, only the perturbations causing it) and then, using the stored histories of 'A and C, integrate Eq. 2.28 back down to the ground, storing each integral from the top of a band to the bottom of a band as the appropriate 27 components of , and resetting the integral to zero before pro- ceeding to the next band. The computational task now reduces to K nominal trajectories, 2K solutions of the adjoint equations and 6K integrals to evaluate over several non-overlapping limits. The requirement for only 6K integrals rather than 12K is the result of the fortunate circumstance tha .t cch rtoc urbation affects only the downrange component of miss distance or the crossrange component, never both. This is a computational task much smaller that the 7K trajectories required to obtain this information for the crudest possible definition of the perturbation quantities p (which assumes that a single number defines the perturbations over the entire range of the independent variable) and very much smaller that the time required if one makes an analysis of the situation to the level that the available statistics would warrent. (This would be on the order of 75K to 100K trajectories.) Some detailed comments on running time will be presented in Section 3.6. I 28 CHAPTER 111 TBE COMPUTER MODEL 3.1 Introduction The purpose of this chapter is to describe the atmospheric and planetary data used in the simulation model, and the model itself. First, the planet-target assumptions will be considered, then the equations of motion, their derivatives and their programming. 3.2 The Planet Model The planet will be considered to be a non-rotating sphere of radius 2.0902286 x lO ft. with an inverse square gravitational force whose surface value is 32.21852 ft./sec 2 . These values derive from the work of Guess and Pelinel. The effect of neglecting oblateness and rotation in the problem is of measurable extent. Utilizing a trajectory program which allows va-' ation in the earth model in both of these effects 18, runs were made with the following initial conditions: Reentry latitude, 52oN* Reentry altitude, 3.0 x 10 5ft. *This latitude gives impacts near 500 North for a trajectory reentering due South at the conditions quoted. This latitude is typical of the USSR, but not of China. 29 Reentry velocity 2.5 x 10 Reentry azimuth 900, 1800, 2700* Reentry flight path angle -200 W/CDA (hypersonic value) lo3 lb/ft2 (CD/CD hypersonic) max 8.0 with and without a 5% density perturbation. ft./sec. Comparison of the rotating and non-rotating oblate earth models and of the oblate and spherical earth models shows maximum errors listed in Table 1. Table 1 also shows the percentage increase in yield and the percent increase in weapon weight implied by this amount of change in a kill radius. The scaling laws employed are those of Sec. 2.1 TABLE 1 Effects of Simplified Earth Model on Dispersion dispertion error yield change weight change rotation neglected 1.127% 3.42% 2.56% oblateness neglected 1.345% 4.o8% 3.05% 3.3 The Target Model The target, as has been indicated before, is a hard, point type target; an example might be a critical command post. its location is exactly known, and it is at sea level, It is undefended, The justifica- tion for the last two statements is that the analysis is not greatly 'i.e. reentry due east, south and west, respectively Fig. 6 gives the detailed shape of this drag curve TI W I t- t- -r- Ii 44 ITE -i --- if I T I -44t 44- I~ II -iTi -- -- tI -T - f 31 affected by the inclusion or exclusion of either item; target location uncertainties (i.e. geodetic and geographic uncertainties) are independent of other error sources, and always will fall into the "random bias" category rather than the "random from vehicle to vehicle" category; impact altitude error is much the same, although the theoretical form of the initial conditions on the adjoint equations will change slightly. Further, these errors are steadily being reduced with the increasing sophistication of geodetics techniques. Finally, the magnitude of such errors for realistic cases is classified. The justification of the assumption of no defense lies first in the complication that a defense would introduce (just as one example, missile system reliability in the sense of catastrophic failure could become a strong function of miss distance, rather than being an independent parameter as before) and second, in the fact that no such system is now known to exist, Soviet protestations to the contrary, as far as the open literature is concerned. 3.4 The Nominal Atmospheric Model The nominal atmosphere used in the United States. Standard Atmosphere, 1962 19* This atmosphere assumes the barostatic equation, and therefore, is defined by a temperature-altitude profile, the nominal atmospheric conditions at sea level, the atmospheric composition as a function of altitude, and the gravitational potential. The assumption of any standard atmosphere is, in part, one of convenience, and ideally one Some checkout runs used the earlier ARDC 1959 atmosphere. difference is not significant. The should use a set of parameters defined as the mean for each target staThe differences between such profiles and the nominal atmosphere tion. are not completely negligible, at least by the criteria of linearity indicated in Section 3.7, and the effect of such an assumption on CEP should be investigated. Examples of comparisons between target station mean profiles and standard profiles are given by Sissenwine, Ripley and Cole 3.5 21 , and more recently, by Cole and Court 22 The Vehicle Simulation The vehicle is assumed to be adequately simulated by a non-lifting particle. This implies that the vehicle's attitude is controlled at reentry so that the reentry angle of attack and lateral rates are small and the vehicle is spin stabilized, so that any residual lift vector is rotated about the flight path, "washing out" any preferential direction for lateral acceleration. Kresa describes a simple scheme for doing this and a conceptually similar scheme is assumed to be used on the vehicle of this study. The vehicle's characteristics can be summed up in three parts. First is the nominal W/CDA (lb/ft2 ), which is calculatedu using the vehicle weight and the hypersonic drag coefficient of the vehicle, together with its reference area. efficient variation. several variables, Second is the vehicle's drag co- While this could be considered as a function of (Mach number, Reynoldb- number and ablation rate) for the purposes of this study it will be a function of Mach number only. There is partial justification for this assumption in two facts: First, the portion of the trajectory where Reynolds number effects are significant is above the region where influence coefficients are large and also 33 re apt to be masked by atmospheric in a region where Cuncertainties Second, the complexity of the interaction between abla- uncertainties. tion and C precludes further analysis at this time. The vehicle equations of motion using time as the independent variable are as follows: t (3.1.3) an(3.1.4) /are 2( ra (3.1.5) (3.1.6) where D = /c0(4) M = Q = aerodynamic drag, lb. (3.2.1) Mach No. (3.2.2) velocity of vehicle relative to the air V = velocity of vehicle relative to the earth g = surface acceleration of gravity R = radius of earth h = vehicle altitude m * vehicle mass 7-o 1~> ( VC(V* Q ((V oA~ G ( V -U C&AC&dL ca* A 4,A)/-(A zY/z (3.2.4) (3.2.3) 34 A= - s(/Ur u, v, w = 4 (3.2.5) (3.-2.6) components of wind relative to earth in x, y, z directions, ft/sec. are defined in Figure 7. The nominal trajectory is simulated on the computer with the simplif ications Q V 0 to Equations 3:and the results written on tape. This part of the procedure requires .14 minutes per case or about 8.4 seconds. Write- out was every 2 sec.ond and the results would be interpreted as altitude dependent functions in the following. 3.6 The Adjoint Problem Dividing Equations 3.JX by3,.l.6 one bbtains (3.-3.2) jkA -WV2,44 (3.3.1) (3.3.3) - q~~9"R(3.3.4) (3.3.5) 35 Figure 7 h -altitude V - inertial velocity 7A yn crossrange distance - S-flig" at path ang le - 7B x - downrange distance altitude Q-vel city \ x-y plane plane normal t V relative to air The matrix B Figure 8 + g ~/3 Cvc64 ) 4G_ -- S o If 0 2?~ (R~ 0 0 V2. R-4-1 T- +1 I? 0 0 0 w. ) V Y~7VWI 3 0 ~4~-C44 0 0 0 0 0 0 -, RC4,C r 0 0 0 R Rcat 0 0 0 0 the mat-ix C Figure 9 pS 2xoo Mnf 2 a, 2ooVVn AC4 0 0 J co Am -fSVCn 2X o -M 44A4 0 Ss cd Y~v M 4 C, ( *-C D) Z d/A -w 0 0 0 0 0 - M+ q) s 5C, ce - psC, 0 \ . 0 0 Ke~ M 38 Forming the appropriate partial derivatives one may write Equations 2.19 in detail as: By + Cp y F S7V S1 p = [ 91P 1oo 7 CD 1 C) Lk - where y= and B and C are shown as Figures 8 and 9. These equations were programmed on an IBM 7094 using FORTRAN II as Avco digital computer program 1562. The basic block diagram is as shown in Figure 10. Figure 10: COMPUTE I NOMINAL TRAJECTORY Computational Scheme Store on Tape compute B&C matrices integrate Ad joint Eqs. up. integrate fundamental formula down program 1562 Program 1213X Print Out The tape storage was used for two reasons: Influence Coefficients First, it allowed use of an existing trajectory program with minimal modification. CThis program used time rather than altitude as the independent variable, but this has no effect on the problem as a whole since the nominal trajectory history is of interest, not the way in which it was obtained. The program is AVCO's digital computer 1213X; no reference has been written for this program as yet. The tape input serves another purpose; the program can be halted while the trajectory output is checked to verify that the program has worked adequately to that time. The following steps are straightforward; a modified AdamsBashforth 4 point predictor-corrector was used for both integrations; 39 the reason for this usage on the integration of the fundamental formula was that it had capability of selecting its own integration interval, which is desirable in cases where the function to be integrated is of a rapidly changing character. This scheme is not self-starting; a standard Runge-Kutta scheme is used to load the predictor corrector with the first four values it requires. The interval of integration on the Runge-Kutta scheme is kept small to minimize the unknown truncation error. Once the procedure has been started the scheme is as follows: 1. a set of values of derivatives are computed at t (using the equations of 1213X as an example) 2. using the last value of At, and the values of the integrals at the last four times, a value for the integral is extrapolated at t 3. t Using the extrapolated values of the integral, new derivatives, at t + 4. + _ A t, are computed. Using the four most recent values of the derivatives, the values of the integrals are recalculated at t + A t and compared with the values obtained in step 2. 5. If this error is above a preset tolerance, the value at t + A t is discarded, the value of f. t is reduced by a preset percentage and one tries again from it. 6. If the error is below a second preset tolerance, the value of ,, t is increased by the same preset percentage and one pro- ceeds to the next time step. 7. This test is for economy. If neither bound is passed, one proceeds to the next integration with unchanged A t. 40 8. This At preselected time intervals, results are printed out. is accomplished by computing the next print time and comparing t + t with it. . If print time is less than t + integration interval, and print times coincide. A t, the t, is reduced so that the integration The case in which one is forced to n, t by this process (t is slightly less than a a very small print time) is dangerous from an economic standpoint, since many integrations must be performed to bring A t up to an economically acceptable level by the process described above. This is guarded against in the following way: between t I+ t and the next print time is checked. A value is less than Thus, A the difference A t, If this A t is set to half this value. t is never reduced to less than half its previous value by the accident of print time coming inconveniently clost tot+ 3.7 A t. Checkout of the Influence Coefficients Using an early version of the program, two check cases were run and compared with the influence coefficients obtained by running nonlinear equations of motion. The vehicle properties used were as follows: W/CDA = 1000 lb/ft2 CD vs M = Figure 6 The reentry conditions were - reentry = 300,000 ft reentry = -200 V reentry = 25,000 ft/sec (case 1) 15,000 ft/sec (case 2) ' = -1 41 The influence coefficients were, in each case, integrated over the entire range of the variable so that there was, in effect, just one band. The results are shown in Table 2. Table 2 Test Cases for Influence Coefficient Generator 25,000 feet per second Trajectory XFalues 590 ft. 0 205 ft. 0 39 ft. 0 Perturbation Adjoi at Values 603 ft. 0 207 ft. 0 u 39.1 ft. 0 38.3 ft. v 0 20.25 0 w 20.17 D,, -wn Cross ' 0 S s a/a Down 500 ft. 0 225 ft. 0 44 ft. 0 0 17 Down ft. Perturbation E/( 1 Cross : Adjoint Values gCD/CD 500 ft, 0 Sa/a 226 ft. 0 43.8 ft. 0 42 ft. V 0 w Cross 0 er second 15,000 feet Trajectory Values 38.oft. 0 16.9 ft. Down 42.lft. 0 Cross 42. The discrepancies are felt to exist mostly in the "Trajectory Values" column, owing to the inherently superior accuracy of the adjoint approach. At present this matter cannot be resolved completely, how- ever, because the adjoint technique's sensitivity to its several numerical integration parameters has not been sufficiently examined. In the earliest operational form of the problem, running time was approximately 26 seconds per case. The excess over the 15 seconds predicted in Chapter 2 is partly due to tape handling and partly due to the inefficient programming which is the curse of early production versions of any program. In addition the requirement of providing extra output from the nominal trajectory program (0.5 sec steps rather than entry and impact only) increased the running time of the nominal program from six seconds to approximately eight seconds. Thus, the maximum ex- penditure of time for one combination of vehicle and reentry condition will be 34 seconds; enough for approximately 11 non-linear trajectories if one is "clever" and runs only from the start of the perturbation. It also is possible to be "clever" with the adjoint technique by running only up to the highest altitude for which statistics exist (generally about 32 km..). By so doing, a further speedup of between two and three can be achieved. Therefore, the 34 seconds can be reduced to less than 25 seconds, enough for about eight non-linear trajectories. The resultant speedup is approximately a factor of seventeen over the previous method, with a concurrant increase in data accuracy. primary purpose of this investigation is thus fulfilled. The (The factor of 17 assumed the data was dividedointoL26 bands fort thO altitude dependent quantities and 6 bands for CD. The sitata was later brought intto line with the level of data available, which represented 71 bands in all or 43 a speedup of only about 9. In Chapter 5 suggestions will be made for the further increase of speed; a further increase of a factor of 1.5 or 2 seems possible.) Limitations Imposed by the Linearity Hypothesis 3.8 The question of the maximum perturbation which would result in an acceptably linear relationship between perturbation and dispersion was examined by assuming a constant value for each perturbation in question and increasing that value until a) it was larger than any reasonable value for a standard deviation of that perturbation of b) the nonlinear relationship between the perturbation and dispersion showed clearly on a plot. These studies were performed at the shallowest 0 reentry flight path angle used in the study, i.e. -20 , since dispersion is at a maximum for shallow angles, and since those quantities which showed least linearity, e.g. density, become less important at steep angles relative to the more linear components, e.g. wind. The results of this sub-investigation seem satisfactory in broad; no such non-linearities were found to be significant. In detail, three substudies were performed. a) Winds were examined at V = 25,000 ft/sec, 15,000 ft/sec and at W/CDA = 1000 lb/ft 2 and at 2500 lb/ft 2 , for a total of four sets of trajectory runs. described earlier. Two of these were used for the adjoint check cases Checks were made for both, down and cross range winds out to 100 ft/sec. the program were detected. No non-linearities above the noise level of In light of this, and considering the simi- larity of the manner in which downrange and vertical winds enter the problem, vertical winds were run only to obtain the adjoint check cases. b) Density and 0D were similarly examined by means of a single set of perturbations since they enter the C matrix in the same way, the results differing only from the definition of the influence coefficient bands. The maximum deviation from linearity obtained were for the W/CDA = 2500 cases, where plus and minus, 10% perturbation impact points were used to compute a nominal impact point by means of a linear interpolation. This was compared with the true nominal impact point, and the difference divided by the separation of the two perturbed impact points. The result was on the order of 3.2%; for 5% perturbations, the error was in the noise level. Hence it was concluded that, since the standard deviation of density is smaller than 5% at almost all times (see Figures 3 and 4, Reference 20, for examples), this problem may be neglected with complete safety. In the case of drag coefficient, for which statistical uncertainties are much less well known, the effect of non-linearities can be neglected by realizing that the division into bands also will tend to prevent non-linearities from becoming significant. d) Speed of sound was investigated only at 1000 = W/CDA. Since this dispersion effect is dependent on the existance of a non-zero d C /dM, it will become very small for large W/CDA because such vehicles impact supersonically. At W/C DA = 2500 lb/ft , and -2 0 O Mach numbers range from above 3 to above 6. i , impact Inspection of Figure 6 will show that the higher values of d CD/dM are not achieved by such a trajectory. Here + 1% differences were compared with +}% differences. Again, the error is in the noise level. The range -1% to +1% was not extended for the large values of C a shown in Appendix B since these occur at higher altitude s and 1) are 4i5 not considered entirely accurate owing to reasons discussed in the next chapter, 2) the influence coefficients at such altitudes are very small, as was discussed above. 46 CHAPTER 4 THE STATISTICS OF THE ENVIRONMENT AND VEHICLE 4.1 A Priori Considerations The quantities which are assumed variable and which can effect the mathematical model described in Chapter 3 were listed in Chapter 2. They form a partitioned covariance matrix as follows: CCODC7 IAtC~rC (4.1) P4?b' - where each element of the matrix represents a sub-matrix giving the correlations between the various bands into which the data was broken. For example, if there are two such bands, the density-speed of sound terms become 0 =k C ,a,~ (4-2) Even though this matrix is 'symmetric, it takes the definition of only a few bands for its size to get out of hand. Are there simplifications? In 4.1, certain terms may be seen a priori to be zero, as a result of the statistical independence between variations in the vehicle parameters and the atmpsphere. Therefore, the matrix 4.1 may be simplified to read: Ot00r ore 'E !YN -, .......- [-A-& scc E -00 0 0 0 6 (4-3) K f~h~r 0Mur~ f~&r~. Arm It can be shown that, for certain targeting philosophies a good many more of the off diagonal terms may be made to vanish. This comes about because wind statistics exist in an earth-fixed coordinate system rather than a down-range-cross range coordinate system. To trans- form from one to the other requires the reentry a imuth angle, and depending on the targeting philosophy, this may be random from trajectory to trajectory. Defining the two coordinate systems, one obtains N y x E Figure 11 W = WN cos W = WN sin 7 + WE sin7 WE cos (4.4) where winds are defined positive blowing toward the north and toward the east. (The specific definition of wind directions used is not import- ant to the following, and meterological usage is by no means consistant 48 during the period over which the references used were written. Compare 23, 24k CAVEAT EMPTORI) . What are the statistical implications of the addition of list of possibly random variables? c. + ÷ A wox~ (WNC 7 %w~ for one of the possible trajectories. L- 45) +- - 4l.6) WE c ez (4-7) There are I density bands and Forming the expectations over all trajectories of DDT J wind bands. 7 and assuming to the Again omitting the subscript k Dz~~ x= 7 , for example, the two reports of France ' to be statistically independent of the perturbations making up V, there results z : Ti~~ ~~ = J pA S ZZAVWr 40 0+ W(4e 4 . 8I e * + Here, p entirely a, u swz8w2- could be any or all of the perturbations which result in .downrang dispensiqn,.i.e titshowswwhat ill happen to, and w. 49 ZZ7 (4.9) - # S JW cnzr S WW ~/&~ A wyj ((S +2Z Wi If' one can say that ~WAI 6 WN 2 7/is 415yW~ 9, 4 We - J WeW S r- (4.i10) z I0 uniformly distributed from 00 to 360 7 -. 2 0 (4.11) and ~7Z -~~ /-1- (4.12) Substituting these simplifications into Equations 4.8 - 4.10 yields r "tT7~~ / Al, A A(5C-v-J74(l.13 A y 4/ J - ( . 3 50 (4.15) This reduces the requirements for statistics to the following, since the values in V which will not be used may be replaced with zeroes without affecting the outcome: O':c o O0 (4.16) ~tO O ~.tQ-o~0, O 0 0 0Tf4 N C) The type of weapons pystem which would show this - distribution most clearly would be a Polaris type 03rtemirith-iCBMirang9, capaableof reaching its target from any direction simply by sailing to the proper geodesic and shooting. For stationary systems, the width of the distribution which can be obtained by reassigning targets and silos at random is limited, and therefore, the simplifications derived above cannot be applied a priori. 51 wa8 determinate and For this study, the assumption was made that 0 equal to 90 , corresponding to an eastward reentry. This choice was made to permit retention of all terms for which statistics had been computed, to allow evaluation of their effect upon CEP., 4.2 The Covariance Matrix V Used in The Study The basic problem concerning V is that it does not exist in full. Many studies have investigated atmospheric statistics; comparatively few of these deal with covariances of atmospheric statistical variables between altitudes. Among those which do, one may mention as being of par- ticular interest the work of Sissenwine et al 21 concerning atmospheric 22 to higher alti- densities, which was later extended by Cole and Court tudes. The former has the particular interest of including pressure covariance data at 20 and 22 km in an attempt to use pressure statistics near the top of the region of available statistics as a substitute for The latter goes the integrated effects of density above that altitude. higher (30 km vs 24-25 km) and gives a very limited amount of data of the wind-density correlation coefficient variety. Charles has provided an excellent set of horizontal wind statis- tical data for the US, including North-East wind correlations at different altitudes, and correlations between different stations at different times. This is a great extension on Court's 26 pioneering work. Charles gives statistics at constant pressure levels rather than constant alti-tude levels as did Court. These data have one great shortcoming: target areas. they do not cover potential For such areas, the work of France 23, 24 * is of interest, At this writing, this is all that is published in this series; more reports are in preparation. 52 although it fails from the standpoint of altitude, stopping at 100 mb. Here horizontal wind statistics are given only for the same component at different pressure levels. The density statistics are given for var- ious altitude levels. The above description is about all that is available in the published literature. Upon consultation with the Applied Climatology Branch of the Air Force Cambridge Research Laboratories, Hanscom Field Bedford, Mass., a convenient set of raw data for 56 stations in the Old World was made available, including several in European Russia. These data, compiled and described in detail by Beelitz et. al. of the Free University of 27 Berlin, are available as Air Force Tape AF 322; extracted from it in brief were the following data at each station: surface pressure, al- titude at selected constant pressure surfaces (700, 500, 300, 200 and 100 mb). Temperature, u and v components of wind and density were also available at each of the isobaric levels and the surface. 360 samples were available, one daily for the months January, February and March of 1955-8. Of these stations, Moscow was chosen. Every third record was taken, to attempt to avoid the problem of non-independent samples, so that the data used consists of 120 samples. Most of the references cited are in agreement that a three day interval is sufficient to eliminate this problem, although the proper period varies as a function of season and of the specific quantity. Linear interpolation from one sample height to the next was used for temperature and the two wind components. In the event of a missing 53 data point,* the data were simply interpolated on a linear basis, as was all data in these categories above 100 mb. The speed of sound was computed from a given temperature by means 20 The density was . of the formulae defining the ARDC 1959 atmosphere computed similarly, using the reference density at the bottom of a given band and the assumed linear temperature profile above. Since the atmospheric density can be computed using the barostatic equation, a temperature profile and a single density value, the data used here are redundant. The effects of such redundancy were investi- gated by comparing the computed value of density at the top of a band, which is at the same altitude. The percent differences appeared to be consistant with the instrument accuracies quoted in the next section, so no further adjustment was made. Using the 120 profiles per station values were computed for the means and variances at two km intervals of all four quantities. resultant The 64 x 64 matrix provided a set of all statistical data invol- ving the four quantities, density, speed of sound, north wind and east wind, for the given stations. 23 These data were compared with those of France tion, to investigate consistency. couraging. for the same sta- The result is not particularly en- While the density and wind stand deviations seemed to be of the same order of magnitude as existing data many detailed differ- The density-density covariances show a change from 21 but their numerical positive to negative at or near the proper point ences are evident. Missing data were indicated on AF322 by a reading-of 0 C. Since these data were taken at night or early morning, in the winter this proved to be fairly unmbiguouiefbrnMos-ow. 54 values, particularly at near-equal altitudes (e.g . 0 and 2 km) seem too high in places (e.g. .8T as compared with .68). The wind-density num- bers agree qualitatively with those of Cole and Court couraging. either which is en- The wind data are not directly comparable with those of Charles or France, since their data is reported on a pressure level, rather than an altitude level basis, however, the standard deviations appear to be somewhat high, as are the means. The conclusions resulting from this data are to be considered as tentative until such time as the data are analyzed in more detail. Two causes of error were suggested by Sissenwine et al;first, that the data used in many other reports relies on more altitudes. In addition to the "standard" pres- sure levels, data are also evaluated at so-called "critical" levels, where the temperature lapse rate is observed to change. The lack of this data would tend to explain the systematically high numerical values of correlation coefficient since there are fewer causes for statistical independence in the reported data. error lies in the treatment of missing data. The second source of It would be wiser, per- haps, simply to concede that the data is gone, since the linear extrapolations will spread apart as one increases altitude. This results in abnormally large values of standard deviation, which are observed particularly for density, at high altitudes in this data. Both of these phenomena indicate that the numerical values reported in Chapter 5 will be too large. The computed results are displayed in Appendix B.* *It will be noted that, rather than the matrix V itself, the normalized version of V, i.e. the correlation coefficient matrix R was used, where Rij= Fij/ C-i a-j 0=1 55 The problem of what to use for vertical winds is very difficult. Data on vertical winds taken simultaneously with horizontal winds is just beginning to be available.* In conversation with N. Sissenwine, A. Cole and I. Lund of AFCRL, two causes of vertical winds were suggested: a) Clear air turbulence occurs from 20,000 ft to 40,000 ft in a layer 2000 to 5000 ft thick. Within this layer, the air rotates in vortices whose axes are horizontal. 20 to 50 ft/sec. The maximum wind speed is from This is to be considered the maximum. This descrip- tion must be considered as very tentative, and open to controversy. It is not more than a place to start, to get order of magnitude effects. b) Fortunately, order of magnitude effects suffice. Convective conditions, such as thunderclouds, cause gusts which may be described as occurring anywhere from 2000 ft to the tropopause. They will be 5000 to 10,000 ft thick, and will have a magnitude on the order of 50 ft/sec. Vertical winds in these altitude regions produce negligible effect on dispersion as the "row 7" influence coefficients in Appendix A. show. This conclusion is strengthened when one realizes that the probability is far from one that these vertical wind profiles will be encountered. It is only the possibility of moderate to strong correlation with other components that motivates the decision to include the vertical wind influence coefficients in the adjoint program. work done on this problem is contained :W an article *A summary by Crutcher , which the author was made aware of too late for specific inclusion here. 56 For this study, the contribution of vertical winds will be neglected in the computation of CEP. The case of drag coefficient uncertainties is also very difficult to describe; unfortunately, there is no evidence that will be small. The author has chosen arbitrarily a 2% value as one (7', with the Mach number bands broken into a subsonic band, extending to M=O.5, a transonic band extending from M=O.5 to M=l.4, a low supersonic band extending from M=1 . 4 to M=4, a high supersonic band extending from M=4 to M=12 and a hypersonic band from M=12 on. These were chosen by eye from Figure 6 as being bands within which the character of the CD vs M curve does not seem to change much. These sets of conditions are assumed statistically independent, to ease the computational problem. In any realistic case the statistical nature of the uncertainties in the drag coefficient curve must be analyzed in detail, considering theoretical prediction techniques and their uncertainties, wind tunnel, shock tube and similar tests, their uncertainties, flight tests, both successful and not and the imponderable, "experience". This is a task beyond the scope of this work. 57 4.3 Adequacy of the Data Since no reasonable drag coefficient date could be obtained, the adequacy of the assumption made in the last section cannot be commented on. With the knowledge of vertical winds in its present state, one must restrict one's attention to four of the components listed originally: density, speed-of-sound, north wind and east wind. Two questions must be asked concerning the adequacy of these data: first, how accurate are the data available, and second, what is the best way of covering the blank spaces in the data. As a matter of con- venience for the discussion which follows, since atmospheric data will be reported both in terms of pressure levels and in terms of altitude, the following table based on Reference 19 gives a comparison between the methods of reporting. TABLE 3 " Altitudes for Commonly Used Pressure Levels p (Millibars) h(ft) (to nearest 100 ft) 850 700 500 300 200 100 50 30 4,800 9,900 18,300 30,100 38,700 53,200 67,600 78,500 20 10 87,200 104,000 No attempt has been made to overcome or evaluate the effect of the possible inadequacies listed here; neither has an attempt been made to be comprehensive. It is highly probable that some of these problems 58 are already solved in the meterological literature, but it is equally certain that some are very much open questions. sented in the same spirit as was Section 2.2: This section is prean unsolved problem is here, and work may be worthwhile. There are two places where such data may break down: the accur- acy of the device which takes the measurement and the adequacy of the way in which the atmosphere was sampled. 4.3.1 Instrumentation Problems The overwhelming majority of measurements are taken by radio- sonde measurements. Current U.S. instrument accuracies are listed in Reference 22, from which Table 4 was prepared. TABLE 4 Accuracy of U.S. Density Measurements altitude (kn) 6 km 1 Density Error 0.3% 12 km 18 km 0.5% 0.7% 24 km 0.9% 30 km 1.2% 23 The case for winds is claimed to be worse, since France indi- cates that + 10 knots may be an upper limit on uncertainty but that this is not a well known area. 23 although Beelitz The accuracy of Soviet equipment is not known 27 indicate that it is biased relative to Western equipment, a et al fact which should be kept in mind. The second problem relative to equipment was first investigated 59 26 by Court and is that wind data at high altitudes are biased in fav- or of low winds because high winds blow the balloon out of range of the ground tracking equipment. Court considers the magnitude of this bias by observing mean winds and their standard deviations at zero and one kilometer altitudes at Patrick AFB, Florida by decreasing his sample size in a selective manner. This selection was made by including only those values resulting from soundings that had dats for progressively higher altitudes. ing at autumn, one finds data as shown in Figure 12. Look- While these data indicate a serious problem, it should be noted that the last few years has seen a great improvement in tracking procedures, and this problem should be reviewed in light of this fact. The next problem is that in general, there is no data over 100 mb for areas of interest.* This was handled in this paper by assuming a constant temperature lapse rate from wherever that data stopped to 30 km. Two other suggestions have been made for filling in data which may have merit, and should be tried. First, for densities, it has been suggested that the standard deviation of pressure at an altitude might be used to simulate the standard deviations of densities above that altitude, since pressure at an altitude results from the integration of density of the A notable exception is the data supplied during the IGY. . - i I I .. 4 t: 4; . j : : t -1 : ,I . , , . .. ,:-,-, , * + , .. . . T,: , t - , I , : , , , . , . t . - - : - , 4 . .i . . . - . 1 , , - L . . I I I:- ] I , - i.. I I V"I I , :, -. ,:, .I - j,-: -,; .... ;, 11 II *. , :-,, . -1- ; i !I . , !, , . i 1'. + - ., I .,:: .. . 1 I11. - I -::.;Ill. -* 1111 111 ,-T-- , + . , , ,, -, ; I, +: .1.I 1. . + . . 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I -fit tt t -1 -IT - 77 F' - 1 - 1- Li $ - 11 -4 - - .7a --l. i;-; F t742 77' - :.x.t 721... t 4, . - 4.4 - '44-. I, A :4.4:. '~1 5Ttt :tt ---- t K1+ - -$ - t - 4" -I :7 14 4ilt' j~ -ui t++,441- I- :4 . :.24: I~ it tiff 4~77 I. -tin -~ I i-: t 44 4 4 -7 -I- 4 AA '44 -K tt 1 --- - 1-- t47 Tt -T- - I . . . .. . .. . _ ___ * :7:1:11 7771 7 47. f [- - - -I ~ttjjt' - -r 1.~ -7K --t- -jt-++ - j 1 --- 1 .. Aitk i 17 II .2 1.7~. '4 -7- LI I H tt44>W 4 tt. $ - - in7.. '-4--I 7:. .4 '-1~ it I I .4 - .4.:: - - -T tp12 - _7T_____ - -. -t *t t 63 influence function curve may be worked out. Sissenwine et al have generated data which may be used to check this method by comparing data from Reference 21 with those of Reference 22 for the same statThe comparison will not be perfect since the periods of record ion. differ, but a start can be made. Second, it has been suggested that the missing data be filled in above 100 mb by substituting data from friendly stations where data at higher levels is available at approximately the same latitude. The results obtained by Cole and Nee indicate that this idea is worthy of consideration. Sampling Problems 4.3.2 The measurement of statistical parameters of the atmosphere may be looked on as an experiment in which measurements are to be taken. As such, the question of proper selection of the measurements to be taken and of a proper interpretation of their statistical significance is important. There are at least seven ways to go wrong in sel- ection of observations. First, the overall period of record may not be long enough. The data of Hering and Salmela 30 suggests the possibility of long term variations in atmospheric parameters. "Although the flow pattern in this altitude range (100 mb-25 mb) is characteristically persistent for rather long time periods, marked differences may be noted in the prevailing circulation for winter months of various years." The example chosen is the 50 mb map for January 1953 and for January 1957. ERR 64 Second, individual measurements may be spaced too far apart, .usualy, radiosonde measurements are taken twice a day, at the same time each day. For example, Charles 25 has taken measurements at 1500 GMT. Considering the diurnal variation in the atmosphere, this may not be often enough. As an example of this, the low level jet stream, long known to light plane pilots in the American Southwest, was not well known to meteorologists because it existed just before dawn and radiosonde measurements did not exist at that time. It was only the con- struction of an extremely tall television antenna in Texas, with continuously operating wind and temperature recorders which made Iszumi's description 31 of the phenomenon possible. The diurnal variation problem is worst at the ground and such variations will become weaker as one rises. This problem will achieve its maximum effect in the case of moderate performance R/V-trajectory combinations, where impact is in the transonic to low supersonic region and influence coefficients for this altitude region are strongest. Here again something must be done; whether showing that, for a few typical stations, the problem is negligible and extrapolating this conclusion to all stations (which has the advantage that there will be no intelligence problem) or that the variations at a few stations are still easily extended to all stations even though not negligible, or having to mount a massive attack on the problem, is not known. tainly our understanding of this problem area is in its infancy. CerOne possible way of determining the significance of this diurnal variation would be to take a series of measurements once every third day (to 65 eliminate persistence) but taken at a random time of the day and comparing the statistical parameters resulting with those resulting from conventional sampling techniques. This would produce statistics which are adequate for CEP purposes assuming that vehicles are not retargeted on an hourly basis, at cost much less than the means indicated by Court and Salmela 32 (which incidentally Will give an idea of what is involved in neglecting this parameter, although the period of record precludes meaningful statistical data. It also gives an idea of what is available in the area of short (less than 6 hours) interval rawinsonde measurements.) Third, simultaneously, in a sense, the interval between observations may be too short owing to problems of persistence. Persistence of an observation has been well studied and seems to continue for 24 to 36 hours (Ref. 21). To be on the safe side, in counting the number of in- dependent observations in a sample, one should not assume observation to be independent until at least 48 hours have passed. this study, 72 hours were allowed to pass. For the purpose of This is most important in ascribing confidence levels to statistical parameters generated. As previously indicated, the values 24 to 36 hours are very rough, and depend strongly on season and on the specific quantity investigated. Fourth, there is the question of how fine to cut the statistics. Should they be annual, seasonal, monthly or what? ing is: The tradeoff govern- As one gets finer and finer increments, the size of the stan- dard deviation decreases because more and more of the uncertainty in the atmosphere becomes bias: The January mean is better for estimating the January 17 density profile than the Winter mean, which in turn is better 66 than the annual mean. On the other hand, the number of measurements available for January is only 1/3 of those available for winter, so that while the standard deviation decreases, one's confidence in it also decreases. Presently the tradeoff point seems to be at the seasonal level, judging from the available published data (seefor example, France 23, 24 )and that is what will be used here for numerical purposes. As more data and more understanding of required data is gained, this may change. Fifth, the selection of break points can be significant. The break- ing of statistics into seasons of exactly three months (December, January, February, = winter, etc.) is arbitrary and is not always the best way to minimize the statistical variation within a time period. This is most evident when one is faced with swift changes in climate such as the onset of the monsoon in India and other parts of Asia or the less well known, much more significant for our purposes and descriptively titled phenomenon of "explosive warming" found in the Canadian stratosphere and described by Craig and Hering. mentions this problem. In Reference 24, France also How far one wished to go in this matter is some- thing for research to decide. Probably people should select with too much care at least once. Sixth, collections of raw data always have holes in them resulting from equipment malfunction, etc. The "raw" date reported on are elaborately smoothed to the extent that such missing holes are not infrequently filled in, using the weather maps of the day to make estimates of such date. Charles 25 and Beelitz 2 and in Beelitz the prodess -used is given. indicate this is done, 67 The Seventh, as was noted, radiosondes drift with the wind. reentry vehicle reenters over a track on the order of 200 miles long for a reentry flight path angle of 200. es: Therefore, the question aris- what is the effect of the fact that the reentry vehicle exper- iences a different atmospheric sample from the sample experienced by the radiosonde, because of the different bearings the two objects take as they move relative to the target? 34i This problem probably is negligible, as Buell, has shown that, to a first approximation, correlations are quite high (in excess of .8 at the minimum) between winds at the same isobaric surface for distances of this order. One may hope that the correlations for densit- ies have the same order of magnitude of distance in their scaling law. 4.4 An Alternate Approach to the Problem A second method of approaching the wind and density problem exists: to generate a synthetic wind profiles'uused in missile guidance system analysis and structural response analysis (e.g. the Trembath wind profile 3 5 ). These, being designed to provide a bad wind shear environ- ment, are not applicable to the CEP problem. The author does not feel this is a useful method, since it is difficult if not impossible to design a synthetic profile for CEP analysis which is independent of the R/V, and therefore it is necessary to reevaluate the profile every time the R/V is significantly altered. For the purpose of obtaining a design number, one may find this procedure attractive since it requires less computer input and less release of sensitive information to contractors, also since it makes proposal-type numbers more 68 directly comparable in design evaluation. The present method allows one to uncouple the reentry vehicle influence from the atmosphere's statistical quality. phere need be described only once. Thus, the atmos- Papers such as that of Beiber36 indicate the increasing favor which the present method has for guidance and structural analysis, especially for research vehicles, where there is effectively only one launch site and therefore relatively few statistics required to describe the atmosphere. MR 69 CHAPTER 5 RESULTS, CONCLUSIONS AND RECOMMENDATIONS 5.1 Scope of the Study rectangular grid of 15 reentry trajectories was chosen, with A velocities from 15,000 ft/sec to 25,000 ft/sec and with flight path angles ( ' e) from -200 to -400, as shown by the circles on Figure 13. As will be seen, these conditions correspond to ranges above the atmosphere (spherical, non-rotating earth) of from less than 1500 nautical miles to more than 7,500 nautical miles. From a launch site in the North Central U. S., no part of the Soviet Union is out of range of these trajectories. Further, most of these trajectories are on the lofted side of the minimum energy line. Two well separated W/CDA's were chosen, to shown the effect They are 1000 lb/ft 2 and 2500 lb/ft2 . of changing this parameter. Only one drag curve was used., shown in Figure 6. to a slender conical shape with a sharp nose. It corresponds The vehicle was assumed to be non-ablating as the ablative portions of the influence coefficient program have not yet worked adequately. This is a serious fault of the implementation of the method detailed. Ablative effects are three in number: First, as material ablates the vehicle looses mass, thereby reducing W/CDA the CD changes owing to and increasing dispersion. Second, the increased bluntness of the tip, again I 777 7777 Al ocr I X3L.LZ 75 &JTTii n:- ............... 7' 4 . k 4, -- 4 i -- t 7t- 77- t - 4-1 Z-7 kl/ 77 777' Aw t wy- -4 i 14 -4 i -l V12 !A t + Ti+ L t f4 jjl -4 .4T 4- tt 4 If + 4-4 4, 14 f Pllllf 7 I 141 F I + , - 4 I i ', t -T 1-4 I 4, I- L 44- + + t Ji 4:vlt t 2- 4 + H tT+, , -1. + 4 4 t 4 +-t-t t T+H T- I t If -4 -4 IT +41 +T 1 4- t +4 T, -44 + t-4 7 14-,- : 44 41 -4 -T: i-Tz 144, I llii.L" L ++++++++4 4 I -.. I i. LL 4T .. -4 jji- i Ht 71 reducing W/CDA. Third, the mass injection will have some effect on CD directly. These effects are most important for a pointed shape, such as was chosen here. tially less. For a blunt nosed shape, their effect. is substan- Also, the magnitude of the effect will be dependent in large part on the nature of the heat shield. Influence coefficients were obtained for the five quantities of interest to the study for each of 30 trajectories;* the drag coefficient in the bands indicated in Section 4.2 and the altitudes in 2 kilometer bands beginning at the ground and continuing to 32 kilometers. Above this point atmos- pheric statistical data are not available generally, 5.2 Effects of Neglecting Influence Coefficient The effect of completely neglecting the statistical variation of the atmosphere above 32 km. was investigated at both values of W/CDA and was found to be strongest for density and next strongest for winds. This was done by dividing the influence coefficient for the region reentry to 32 km altitude by the influence coefficient from reentry to ground. The maximum values for density were found in the upper right hand corner of the V- 1 map and were approximately 4.5% for the W/CDA W/CDA 1000 lb/ft = 2500 lb/ft2 0 and approximately 101 for the These results are shown in Figure 14a and b. The reason for this trend, and for the dramatically different charac- ter of Figures 14a and *Actually 29 cases. 1 4b, is that there is a large increase in The W/CDA = 1000 lb/ft2 Ve = 15,000 ft/sec and te % -35O case was lost due to an input error. This error was not retrieved since it was discovered that the plots did not require the inclusion of the point. El It FIR 1-,ikr~t ti+t-4- tt+--ttH . .. V -I HI III 1HtnMM++~+tM4 4 $44 11 ' : I : i I Rf4th iT I t~t+ 40 "W"o-T - _____________ - A ............. I I' - I ~ ~ I I 77 ~z~EET /~B 44J~j *g ~MI4A~4 L AKk~rbrfL ~7V77~IV74 1+-i-H III- I i -41J ~1 .4-i t -Itt ti' t I I ----- -14 '--1- LizI I I IWLL~ j Iii - ~ -4- ~Th-~ A __ ... 1- '----4 t4-~1 I IN ~i 7~ - ,- - - -I----- . *-,-Y- - , t _ _ _ '14~ 4+j4 ii7- 1 LIa -1I_ ltLV t-- _ - - -7 7T_ i4 4- I 1' II -I FT]7TV 147 { LiI11 I Fl 4HILI TIT7 ~7I7f47I+ L Li 41 77177I i-fl't~T -4 -- TLILL - ---4 4- 7-7 1,7- 7 f 4 .21':. fr~2fTj7] ti~ 4-': t, *N 4- 1> H 1~i f! 1'7 14 ~iLJ I--- I ii2 ~ F I r ......... !:H4 + T it T + 4 - 1 + it 4.J - - A>~41 Ih1~-i4-+TiU~i~$$ sKddThITfA + X I '1 1 4. 1 + pj - ti tT t '4 11 144{t~ I I 4~ i t1 + "t f i -- T t-+ I TT TIT +t-4- 44I ~ ih$PKt7I~Nii4$ 4-' 4 t~4~~5LLLL I T- "v 1+ -4 4 4-1 4 Ui f I:t 1111-~1;---------- 1T"t-11 ltl 't-t-i11t-11r 1T RT +_' +f+t ti 14tt444 +121+4 --42K 144-4--I 4444-44 4 + H 11T t f4t f++ I,- itilt44 11 -44 -4. LIL.L-1 L-k II '+4 1 t,-4t,441 41$ A;- 14 -1-- 444 4-4-44 4-4 4-4 _iL IT r + + - + 4, 4 . 14 - t-1 j4 ..Y .i. .ii .I. 4- +4 44-4- -4-44 4-4- +-#-+444- -i-f4--i 14.i N T t],7TIIr j,? E~Il. 1 th 4 4 iI 4 i "1 4 1 t -t I 1 74* dispersion due to density at low altitudes which result from the CD factor and the d CD/dM term in B(ll) (See Figure 9). The correlation between impact Mach number and the percentage of density dispersion shown below 100,000 feet is striking. Cases 4, 5 and 10 (Figure 13) are the only ones which showed supersonic impact in tne W/CDA = 1000 series, and there is a slight increase in impact Mach number toward the lower left which corresponds closely with the shape of Figure 14a. In Figure shown. 1 4b, all impacts are supersonic, and no irregularities are The Mach numbers at impact are shown in Figures 15a and 15b. The lower left hand portion of Figure 15a was virtually flat, and plotting was not possible, however, a very slight increase was observed as one moved toward Case 11. The correlation between high impact velocities and high percentages of density influence at altitudes where the statistics are unknown is fortunate, for it is at these high impact velocities that density has its smallest relative contribution to the whole of the downrange dispersion. To show this, the effect of perturbing density by a uniform 1% was compared with the effect of a one foot per second downrange wind and the resultant ratio shown in Figures 1 6 a and 16b. The data of Figures Pa statistics of the and Pb are optimistic since the actual atmosphere are not considered. These will increase the indicated percentages for two reasons: First, generally increases with altitude at high altitudes Second, the use of several bands in lower altitude ranges will tend to decrease the contribution of the lower altitude ranges. Therefore, r~- k -4- 4+#__" I Ql TT T + 4_1 -4-4 + + do, _41 , -+-- tmvr 4- +4- t L EMri-IITT F7T -t ii iii t 4- A _ t## -t 4-4 + 'A41tt 1#4 4- 4 - j- 4- 2 -T _Tj- #i -4-, -4-- f T r 1-'-'--- 4 + 4_ I F-L H-f-' r ft f-i _f# 4-4- - ~L~-~ _ ii _7 V71 - +4 Z : t 4- 1 -4 + 4 I Ir I -- 44 ILL ti tT I~ t L+ +1 T, + ....... ..... I 4 -4-, -44 4 -414 t+- -- -1-4- T:L '-~ t-t- -4- -4 4-4- t -4-- ::ti tt -1 4-' -I- !7,4ii t4- ~~ 4 t4 -4 TTT t4 -4- '1 4- 7t 5 T-pi 1-- '4-- I ttItth t -4.t4 4L+ 4 -4- k~lt~t -"t4 -4-+44- 4-t7Kt 1, 444 -+-4 + + -- - + ;x ii - lttl -4- T 11 r4 - 4-4--, T 4+ T T F" i 4-+ -4 ~~rrfrd IVT 17l 4 mrr I~tt - tMh~c14444 T-1* -t- + -4- rn t4irtt~LtS4t 4- LIL fua -'4 b4 t ~ThX~TTTTh It~~~ -4 1 +t~f77& 4- 4 -Z~tL5Il~t~-4 4i' -I- T- 1 4z tf~IT~ tr-l .. . . -4- , f Th-'-L$.~9HH11+1+h -4-44 t-+ 47CT r T I 4- - -t I41 I -4 4_1 4 Ft-:tA W 41 4 t + 4* I -4- " i tr~ + TT - 44-- ITt IT f i+ .1 IrII II t4 -T-' IIItI ,4 I __ 4 -- - -t~~~~- 4It 7 I- yE * 4-4-' -tr -- I--44-'-, t4 ~j., 7214- - 1 1 +.. -,---4 4 tjr -4-- T-44-- 4 I-4 -tt ++' It ~ ~ t t t - , 4 -tr M: I, I14, -r 4 4--. . J-4 t It -4HJ 1 -- -AI -4- 4- - t- -- --4-4,, '---_i; .- 4 "' + C T&r -- +- .- 4~ !4- - t4 4 " 4 - -- 4 Wrl12<4--r7 -4 tz --- 44 tT Wh l .. l . 14THWO11 j qiq 14 -t M tl -T: t k-'t#~; 'IF P4r 1 t T 4 ; 1. Q 'j ;! l l Jk Is I -t~~~~~i F1:f~f, ~ttitt 1.. 1.: -'--4 1 -t'' 'I' I I ' "~~4 i i l, ~ tti~A - - 1litFF in lt1 1V 4+ 7 7, i T- - - + '~IA >4 -~ I4 lt I I' I1__L1WhT 14T - 1 4?HVAIIF2Li 1 4kJ\O fVIM . - 4 1. -- i - T - 4 4 1 T .17 t 4-4 74 n rI sot: 44 4,t 2+ 111 F1 m _:T 717 II 171 . -~~~ -- 1-- j- - 4-. - 41 '4-, 1 -4-i4- . :-' . . . . ... -A 14 -~1' LI . _ _ 14 T N -41 1- [~-.iL-.~ 4 42. 4 --- 1 4 ~ 44j 'II~24*~I *1~4- __ rL 4 7 t-4 It\ 4z~ 441 t7f I[ IA. ftL -t-. t7LI7~w b~~' JzLL2KL~L A 4 i -- 4--. 4 + - -4 4-. T --.1- 1 4 7 I--k II I -4F -14 4 4-j-4~4 ti 4 I __ 1~' 44, I 4'T + t t:11 44 H 4+ T +4 -t-t41 F T tl t- _I t .++ 44 + t4-. 4T t TT - I . . II . . -4 4" _64__Jiq 1 + ' J- J -!-__ -' ---- t 4 -fit I II t II I 144 t t7 79 the true percentage of influence above 32 km may be expected to be higher than reported. The percentage differences for speed of sound were found to be negligible, as would be expected. 5.3 CEP for Various Combinations of Statistics The basic CEP's shown in Figures 17a and l7b are for the full set of Moscow statistics and 2% variation in CD as one standard deviation. It will be noted that, as would be expected, CEP's increase with decreasing velocity, with the exception of a small region in the lower left hand corner. The reason for this effect is bound up with the the increase with decreasing velocity will become less important at , large values of influence coefficient at low Mach numbers; therefore, higher W/CDA and also for the same W/CDA for a lower drag rise shape0 The values of CEP for cases 1, 6 and 11, at the far left of the figure are tabulated in Table 5. Figures 17a and 17b and Tables 5 and 6 include only the effects studied here, i.e. horizontal winds, density, drag coefficient and speed of sound. Therefore, the CEP's reported in Figure 17 and in Table 6 are to be taken with a grain of salt. tending effects at work: There are two con- first, the atmospheric statistics probably are biased to give too large estimates of CEP and second, there are many excluded contributors to CEP which tends to make any estimate of CEp computed here too small. Some idea of the effect on CEP of changing the accuracy with which CD is known may be gathered by changing the percentaogo used u5 a 1 Crvalues of CD uncertainty0 The improvement resulting from re- ducing 2% to 1o was investigated, as was the degradation resulting 4_ +1 -1 r >'4'" ._ 4444 7W77YVF 1 t' - __ -.4 AC T_ H 44-4444 bi4jrnjj T - 4 p + I 'T ,14:T r-TJ+ 4-4 44 211 ''1LL2i~it~A~ T11 I L I 7VFI17z 4t _TI7FT 4- -i- 9 f-t It $1 *1 - ,21 l+tU 1 i fj Kt4Th-~t 2-Li' rwf7N+~- 1 [a-'P4 br4 LW tl~ itt jz4j ~tL2V~ 7 7F47 1,4 I-~~ -P I~ i ~ f Wi#~Ht4zUI_4zi4 t ft Wflt-4#7 Iii 1~hLkff S 71442-t 1171171 -1 A 4 - 2 5' 44 4H T f .--. - sI a I 8 tiii }t- __ 4 1 k4141 14 4;a JK 4W4 4 1 j, 4 t 4 ~4 T 1 t .2$,~4 4 4_1 h1f TI I t 211 4' { 4 L44 t 1 4t4 L4 f4 _ Ii 82 from an increase to 4>. Considering the drastic change in CEP re- 2 2 sulting from changing W/CA from 1000 lb/ft to 2500 lb/ft , the results were comparatively constant. Their maxima are reported in Table 6. TABLE 5 Atmospheric CEP at Ve (ft/sec) W/CA 1000 lb/ft 2 = -200 W/CA 2500 lb/ft2 25000 2481 237 20000 2500 278 15000 2433 304 The effect of not using certain of the less commonly available (and therefore, less well studied) atmospheric parameters was investigated by first blocking out the terms in the atmospheric matrix pertaining to speed of sound and second by additionally blocking out wind-density correlations. These data also are reported in Table 6, as the percentage increase in CE resulting from including these terms if they had not been included previously. As before, the percentage change in weapon yield and in vehicle weight (assuming R/V weight is proportional to weapon weight) which is required to keep the value of kill radius/CEP constant in the face of these changes are included. 5.4 Conclusions 5.4.1 General: While the adjoint method of Bliss is not yet fully worked out for all cases of interest to which it is well adapted (notably dispersion due to ablation) it has shown itself to be a quick, TABLE 6 CAUSE W/CDA Decrease in CD 1000 4 -2.86 -8.45 -6.26 uncertainty to 1: 2500 11 -2.21 -6-78 -5.05 Increase in CO uncertainty to 4% 1000 2500 3 11 10.97 8.37 36.7 27.3 26.4 19.7 Inclusion of speed of sound terms for the first ti.me 1000 2500 11 11 2.05 1.09 6.29 3.31 Inclusion of speed of sound and of wind- density correlation terms for the first time 1000 2500 6 8 CASE CEP CHANGE, 10.4 6.9 % YIELD CHANGE, % 33.1 22.15 R/V WEIGHT CHANGE, 4.84 2.48 23.9 16.2 % MAXIMUM EFFECT ON ATMOSPHERIC CEP OF ALTERING CERTAIN ELEMEN'S OF THE COVARIANCE MATRIX V 00 84 economical and accurate way of computing several components of reentry For the thirty cases of this study (including, for this vehicle CEP. purpose, the improperly run one) the total machine time (using an IBM 7O94-I) used for getting the required influence coefficients was of the order of 9.5 minutes as opposed to about 95 minutes using the approach of subtracting impact points gained from non-linear trajectories.* Further, experience gained in the checkout phases of this job, together with an understanding of how Equation 2.27 is integrated indicates that the only expense involved in increasing the number of bands pointed out is in the printing out itself and the additional choices of 4 t required to make print steps coincide with integration steps. From this, one may conclude that, while much still can be done and should be done toward improving the efficiency and accuracy of the adjoint program, the greatest gains will be made by investigating the other causes of CEP and the missin,. atmospheric statistics. It is concluded that the statistics available in the open literature are not adequate to do an acceptable job of computing CEP without making many assumptions, the effects of which are only beginning to be analyzed from a CEP viewpoint. Comparison of the data in Appendix B with data obtained by others shows that the use of constant lapse rates to extrapolate temperature and winds is not adequate, also that not including the data at "critical" levels has a startling effect on correlation coefficient. *Fortunately, the latter number is only an estimate. 85 5.4.2 Design: The amount of drag rise in the transonic region is of overriding importance to CEP except for very high performance vehicles; it may well be that there are shapes which, while they do not have as good performance at the hypersonic end of the CD curve, where W/CDA is defined, have sufficiently better performance where drag rise is concerned to make up for the reduction in W/CDA. 5.4.3 Procedure: Which of the atmospheric parameters may be neglected depends on the uncertainty with which kill radius is }nown. Obviously, if kill radius is only known to, say, :+ 10, a reduction in th uncer- tainty with which CEP is known from 35o to 24 isn't ";oin; v :e much in terms of how well kill probability is known. However, Iere are some conclusions which may be reached as to the order of attack: Probably the CD uncertainty (1 C-) at which the point of diminishing CEP returns is reached is on the order of 3%, although more can be tolerated if analysis shows that the Mach number regime from 4 on up can be divided into more statistically independent bands. The next statement that can be made is that, winds are the most important contributors to CEP, and greatest effort should be concentrated on getting good wind information. 5.5 Recommendations for Further Study 5.5.1 The trajectory Model: The first cut at the effects of ablation should be included. The level to which this may be done probably will be limited by economics as a full ablation analysis is long, complex and costly. 86 There is a possibility that winds induce a residual lift that is not "averaged out" by the vehicle's spin. This should be investi- gated, particularly for high L/D shapes such as this study used. 5.5.2 The Computer Model For various reasons (convenience in plotting, etc.) it has been customary to print out trajectory histories in equal times or altitude increments. This practice was carried over into the data storage of the programs reported here. and in fact it may be undesireable. There is no need for this, By printing (or storing) at each integration interval, one does not perform unnecessary computation to match print and integration steps, one does not create data that are not needed for accuracy, and conversely one does not ignore data that are needed where the data to be integrated vary rapidly. Some idea of the cost involved in matching print steps and integration steps can be seen when it is realized that, in comnu- ting the nominal trajectories with printout every 1 second, the machine time increased by about 50% over what was required when only the initial conditions and impact conditions were printed out, If a special purpose operational CEP calculation program is to be written, the segmentation into two parts linked by tape probably is not desireable. It is not needed on a 32,768 word machine, and tape is a slow storage medium. The precomputation of the matrices B and C should be reviewed, as should the specific integration scheme used. Lastly, the usual cleaning up of the programs should be made, such as removing unnecessary instructions and the adjustment of integration controls 87 to optimize the program's running. should be relatively sinple from an analytical standpoint to expand the analysis to include the airburst case ( It conditions) essentially by changing the initial conditions on . it to compute the perturbations in any interestin. -erminal (Perhaps one may have to introduce addition state variables, as well, such as t.). Finally, as a more remote possibility, the adjoint process described here is one half of the interactive optimization scheme known as 'the meghod of steepest ascent." Should it prove feasible to determine the exchange coefficients between zmall changes in vehicle shape and CD vs M curve, the possibility of closing the loop by shaping the drag curve for minimum CEP may prove fruitful. This possibility rests on the potential tradeoff between W/CDA and the amount of drag rise noted in Section 5,4.2. 5.5.3 Computation of Meteorological Matrices Suggestions for improving the raw data will be found in Section 4.2 and 4.3. There are three things which should be done in the area of reducing this data. First, there is nothing sacred about constant width altitude bands, just as there is nothing sacred about three month seasons. Other band widths should be tried, both from the standpoint of reducing the number of bands required and from the standpoint of improving the accuracy of the data. Second, the means of extrapolating data above the altitudes where it is available should be reviewed. As was indicated the 88 constant lapse rate assumption used here probably will not suffice. Third*, while these data are correlated, there is a linear combination of them which are not correlated, obtained as the components of the eigenvectors of the covariance matrix V. The possibility exists that these data will present a comparatively few independent random variables, which may be more meaningful particularly if noise. the less important ones can be interpreted as The implications of this possible condition on the validity of applying the Central Limit Theorem to the problem should not be overlooked. The Target Model: 5.5.4 Three things were assumed in order to make this analysis feasible. First: The restriction to ground burst fuzing does not present any great mathematical difficulty to remove as far as computing CEP itself goes. However, the inclusion of airburst error into CEP does present a problem in that it cally. links CEP and kill radius statisti- Since CEP itself is of interest only as an intermediary to obtaining kill probability, consideration should be given to determining kill probability directly from the detonation point probability ellipsoid, something which should be entirely feasible with the adjoint method of analysis. Second: In connection with the above, the possibility of The author is indebted to N. Sissenwine and A. Cole for raising this point in conversations with the author. * 11 89 including area targets with variable shapes, sizes and priorities of regions within (a power plant is more important than a suburb) raises considerable room for investigation. Finally, the most challenging relaxation analytically results when the target is allowed to shoot back. The tradeoffs involved for the offense are essentially how much payload goes to increasing kill radius, how much to reducing CEP (high W/CDA shape, attitude control system etc.) and how much to keeping the defense from knocking you down (penetration aids: decoys etc.). The various combinations of offensive and defensive doctrines available should keep high-speed computer stockholders happy for a long time. 90 APPENDIX A SAMPLE COMPUTER OUTPUT FROM ADJOINT PROGRAM Four cases were included to show the output and its format. They are from the W/CDA ~ 1000 set, and do not include effects above 32 km. TABLE A-1 REENTRY CONDITIONS FOR CASES SHOWN CASE NO. Ve e 1 25,000 ft/sec -200 5 25,000 ft/sec -40 11 15,000 ft/sec -200 15 15,000 ft/sec -4O For each case, 6 pages of output are presented. The fourth row is reserved for ablation when it becomes available. For each case the column KK is simply an output count; the column ALTITUDE (FT) is the altitude of the bottom if the appropriate band, and DOWNRANGE and CROSSRANGE coefficients for the respective bands. are the influence The upper altitude of the 91 uppermost band is 104992.0 ft. (32 km). In the case of CD vs M, the altitude printed out corresponds to the altitude at which one passes out of the bottom of the corresponding Mach number band. The Mach number bands are slightly discrepant from their description in Section 3.2 in that the transonic band is here subdivided in two at M ~ 1.1. Therefore there are two transonic components to the CD influence coefficients rather than one, and the fourth and fifth contributions should be added together. Finally, it should be noted that these data do not extend to 300,000 ft., as did the check runs in Chapter 3, so cases 1 and 11 here are not directly comparable to the data presented in the check cases. ROW NUMBER ALTITUDE(FT.) 1 DENSITY DOWNRANGE CROSSRANGE 98430. -0. 3637E+01 -0. 91868. -0.4805E+01 -0. 85306. -0.6384E+D1 78744. -0.8527E+01 72182. -0.1 14 E+02 65620. -0.1-534E+62 .7 59058. -0.2060E+02 8 52496. -0.2756E+02 9 4 59344 -0.36862+02 10 39372. -0.4933E+02 32810. -0.6522E+02 26248. -0.3176E+02 19686. -09952E+02 14 13124. -0.1111E+03 15 6%2. -0.2302E+02 16 C. -0.6180E+02 KK -0. -0. 3- -0. -0. -0. -0. -0. -0. -0. 12 -0. CASE 1 V 25,000 ft/sec = -2 0 0 92 -0. 0. -0. SPEMi ROW NLMOER 2 ~ SCUND DUWNRANGE CROS SRANW 98430. -0.2685E-C1 -0. 18 91868. -0.3524F-01 0. 19 853)6. 433E -01 -- 20 78744. -0 .6088E-01 21 72182. -0 .756E-01 22 65626. -0 .1033E-0 23 59058. .1317E-00 -0. 24 52496. ^ .?42RE-00 -3. KK ALTITUDE(FT.) 17 _ -0. - - OF 45934. 26 39372. l-0. .17OF2 27 3281C,. 28 2629. 29 19686. 30 13124. 31 6562. 32 0. 0. .P914 F -12~52Er+01 CASE I V = 25,0 00 ft/ sec = -200 93 -0 ROW NUMBER 3 DRAG COEFFICIENT DOWNRANGE CROSSRANGE 33843. -0.2365E+03 -0. 34 17790. -0.2378E+03 -0. 35 13196. -0.7766E+02 -0. 36 5298. -0.5093E+02 -0. 37 0. -0.2153E+01 -0. KK ALTITUDE(FT.) 33 CASE 1 V 25.000 ft/sec =-20 94 ROW NLMBER 5 DOWNRANGE WIND KK ALTITUDE(FT.) 42 98430. 0.105&E-O0 -0. 43 91868. 0.134!E-00 -0. 44 85306. 0.171!E-00 -0. 45 78744. 0.2189E-00 -0. 46 72182. 0.2802E-00 -0. 47 656?0. 0.3609E-00 -0. 48 59058. 0.4680t-00 -0. 49 52496. 0.6094E+00 -0. 50 45934. (.809E+0O -0. 51 39372. 0.1089E+01 -0. 52 32810. 0.1496E+01 -0. 53 26248. 0.1874E+01 -0. 54 19686. 0.2430E+01 -0. 55 13124. 0.6455E+01 -0. 56 6562 0.2747E+02 -0. -0.3202E+02 -0. 57 DOWNRANGE 0. CASE I V 25,000 ft/sec =-200 95 CROSSRANGE CROSSRANGE WINO ROW NUMBER 6 DOWNRANGE ALT ITUDE C T. T) CROSSR ANGE 98430. -p. 6 .1030F-0W 91868. -0. 0.1316E-0 85306. -C,. 0.916,80E-00 78744. -0. 0.2156E-60 7Z182. -p. 65620. -0. 0.3546E-00 0.4567E200 59028 -p. 67 -0. 52496. 45934. 0.5872E+O0 O w76C4:E+00 3932. -0. 0.9944E+00 68 32810'. -0. 0.1325E 01 69 26248. -0. 0.1780E+01 19686. -0. O.2857E+'Ol 13124. -0. 0.7137ME01 ILa 6562. , ,.0 0 *15 71E -0. 0. CASE 1 V = 25,000 ft/see 2= -20 96 0.4567E+01 ROW NMBER KK ALTITUDE(FT. I VERTICAL COWNRANGE CROSSRANGE 98430. 0.202 8E-00 -0. 75 91868. 0.2518E-00 -0. 76 85306. O.3121PE-00 -0 77 78744. 0.3859E-00 -0. 78 72 82. 0.4731E-00 -0. 79 65620. 0.5770E+00 -0. 80 59C058. 0.6978E +00 -0. 81 52496. 0.8284E+00 -0. 82 45934. 0.9598E+00 -0. 83 39372. 0.1101E+01 -0. 84 32810. 0.1237E+01 -0. 85 26248. 0. 1423E+01 -0. 86 19686. 0.1989E+01 -0. 87 13124. 0.3384E+01 -0. 88 6562. -0.5870E+01 89 C. 0.2341E+02 CASE I 25 000 ft/sec =-20 97 . 74 -0. -0. ROW NUIER 1 KK 2 3 ALTITUDE DENSITY T) DOWNRANGE 430* 036:9-- 91868. CROSSRANGE 0-0 -0. -0.1729E-00 -0. 6. -0. 2200F-00. 4 78744. -0.2754E-00 -0. 6 656200. -044B4E00 -0. ... ~056 7 8 52496. 9 45934 0#58 62 E *0 -0.7144E+00 0. -0. M63E+00 10 39372. -0.1099E+01 -0. 11 32810. -0.1326E+01 -0. 12 26248. -0.1502E+01 -0. 3 1984 -0 14 13124. -0.1588E+01 -0. 15 65620. -0.1336E-+01 -0. 16 0. -0*4833E-00 -0. CASE 5 V = 25,000 ft/seC 0 = -4 0 98 00 ROW NUMBER SPEED OF SOUND 2 0 OSRANGE DOWNRANGE 198430. -0 9 8 -0. .1026E- -0. *-6,1294E-02 ~-0,1640E-020 * -0. *-0.2041E-02 ~-0.2570'E-02-0 * -0. 3972E-O2-. 9058' Z. 24 0. -6.3232-02 6562* 52496. -0.4806C-02 -0. 25494* -0.566 -0. -0 .0 1 -* .... Z63 0. 321D 188 7E-0 -0.2087-0-0 29---- 9 660-169nE+0 31 0.1454E+ 3*0 CASE 5 V = 25,000 ft/s-ec = 4 99 -0. -0. [ RO NU KK ER 3 ALTITUDE(FT.) DOWNRANE 3082. -Q.4015F+O1 6 .966 CASE 5 V = 25,000ft/sec 0 = -4 0 0o0 CROSSRANGE -. 5 090: * 34 ORAG COEFIC ENT -4 -0. -0 ROW NUMBER 5 KK DOWNRANGE WIND DOWNRANGE ALTITUDE(FT.) CROSSRANGE 40 98430. 0.3280E-01 -0. 41 91868. O.4186E-01 -0. 4 85306. 0.5384E-01 -0. 43 78744. 0.6781E-01 -0. 44 72182. 0.8687F-01 -0. 45 65620. 0.1124E-00 -0. 46 59058. Q.1433E-00 -0. 47 52496. 0.1842E-00 -0. 48 459134. 02313E-00 -0. 49 39372. 0.2964E-00 -0. 50 32810 0.3732E-00 -0. 51 26248. 0.4487E-00 -0. 52 19686. 0.5417F+00 -0. 53 13124. 0.6331E+00 -0. 54 6562. O.7597E+00 -0. 55 0. 0.8281E+00 -0. CASE 5 V = 25,000 ft/sec =-400 101 CROSSRANGE WIND ROW NUMBER 6 DOWNRANGE ALTITUDE(FT.) I LRUSSRANGE~ 98430. -0. 0.3232E-01 91868. -0. 0.41469-01 85306. -0. 0.530E-01 78744. -0. 0.6783E-01 T2i82. -0. 0.866SE-01 61 65620. -0. S0 1109E-0 62 59058. 63 52496. 64 45934 560 0*e142 E -00 -0. 0.1810E-00 0.2303E-00 -0. -p. 39372. 0,2932E-00 32810. 0 - 36'97E-00 67 26 0.4469E-00 68 19686. 69 13124. -0. -0 0.-6259 E +M 70 6562. -0. O.7622E+00 't8 0e5283E+00 0.7028E+00 CASE 5 V 25,000 ft/sec -4 = 40 102 PEP ROW NUMBER 7 VERTICAL CROSSRANGE ALTITUDE(FT.) 72 98430. 0.3732E-01 -0. 73 91868. 0.4764E-01 -0. 74 85306. 0.6128E-01 -0. 75 78744. 0.7715E-01 -0. 76 72182. 0.9880E-01 -0. 77 65620. 0.1278E-00 -0. 78 59058. 0.1627E-00 -0. 79 52496. 0.2088E-00 -0. 80 . DOWNRANGE KK 4593 4 0.2616E-00 -0. 81 39372. 0.3344E-00 -0. 82 32810. 0.4195E-00 -0. 83 26248. 0.5C17E+00 -0. 84 19686. 0.6047E+00 -0. 85 13124. 0.7133E+00 -0. 86 6562. 0. 8702E+00 -0. 87 0. 0.9C58E+00 -0. CASE 5 V = 25s000 ft/sec = -400 103 r ROW NUt4BER I KK ALTITUDEF 194 30 2 91868. 3 853060 4 78744. OENS1TY DOWNRANGE CROSSRANGE -0.3794E01' -0. -0.4933E+O1 -0. 0.6447E+0 -0. -0.8480e+01 -0. 0.11)8E+0Z -00 6 65620. -0.1483E+02 -0. 7 51050. -0.1966 E-02 -0. 8 52496. -0.2601E+02 -0. 9 45934. -O.3444E+02 0. 10 39372. -0.4549E+02 -0. -0.5936E+02 -0. 12 26248. -0.7404E+02 -0. 13 14686* -0. 8700E+02 -0. 14 13124. -0.8530E+02 -0. 16 6562. -0.28975+02 0. 0.7945E+01 CASE 11 V = 15,000 ft/sec S= -2 0 0 104 -0. ROW NUMBER 2 KK ALTITUDE(FT.) SPEED OF SOUND DOWNRANGE CRO$SRANGE 17 98430. -0. 4549E-01 -0. is 91868. -0.5887E-01 -0. 19 85306. -0.6963E+0O0 20 78744. -0.1275E+01 -0. 72182. -0o.1644E+01 -0. -0. 2109E+01 -0. -0. 2658E+O1 -0. 23 52496. -0. 3269E+01 -0. Z5 45934. -0. 440 8E+01 -0. 26 39372. -0.2161E+02 -0. -0 27 32810. -0. 3626E+02 28 26248. -0.5361E+02 29 19686. -0.7229E+02 30 13124. U.1646E+U3 31 6562. -0.1068E+03 32 0. 0.5732E+00 . 24 -0. -0. -0. CASE 11 V = 15,000 ft/sec = -200 105 -0. DRAG COEFFICIENT ROW NUMBER 3 KK ALTTUDE(FT.) S51956. 34 23057. DOWNRANGE -0.9768E+02 -O.2548E+03 37 5271. 0. -0. 0. 692 180.8622E+02 36 CROSSRANGE -0.6727E+02 -O.1596+2 CASE 11 V = 15 000 ft/sec = -200 106 -0. 0. ROW NLMBER 5 KK ALTITUDE(FT.) 42 843. 43 91868. 4 DOWNRANGE WIND DOWNRANGE CROSSRANGE 0.1402E-00 -0. O.177CE-OC -0. 530. 0.2203E-00 -0. 45 78744. 0.2778F-00 -0. 46 72182. 0.3534E-00 -0. 47 65620. 0.4529E-00 -0. 48 59058. 0.5829E+00 -, 49 52496. O.7561E+00 -0. 50 45934. 0.9951E+00 -0. 51 39372. 0.1205E+01 -0. 52 32810. 0.1604E+01 -0. 53 26248. 0.2407E+01 -0. 19686. 0.3537E+01 -0. 55 13124. 0.1538E+02 -0. 56 6562. 0.6972E+01 -0. 57 0. 0.1410E+02 -0. 4 - CASE 11 V = 15,000 .= -20 107 ft/sec CROSSRANGE WIND ROW NUMBER 6 KK 9186 8 60 85.6 61 78744. 2rfl ]o 2 62 63 652.-0.O.14E 65 52,496.-.063EO -0. 0. 1615E-0 0. 092044E-00 -0. 092593M-00 -0. 0*3290E-00 O0 6983E+O0 66 4 15934:,i -0. 67 39312. 0 68 3280 -0. 69t 1 ~ .14EO .15E 0, 2389E+01 26248.-0 04483E+01 -00 1968bu . 71 0., 1451E+OZ 132.-0. 6562* '3 0. 1276E-00 -0. 898430 59 CROSSRANgE DOWNRANGE ALTITUDE(T. V. -00 L~?U I .'tV~ IJ vel+V;JILCT L -U. U. CASE JII IS 000 V -y 200 . .. 1 %* 1U 9 ROW 7 NUMBER 7 RD NUMBER KK ALTITUDG(FT.) VEf~~ICAL VERTICAL DOWNRANGE CROSSRANGE 98430. O.2053E-O0 -0. 75 91868. O.2517E-00 -0. 76 85306. 0.3091E-00 -0. 77 78744. 0.3776E-00 -0. 72182. 0.4553E-00 -0. 79 65620. 0.5448E+00 -0. 80 5905$ 0.6413E+00 -0. 81 52496. 0.7384E+00 -0. 82 45934o 0.8370E+00 -0. 83 39372. 0.9880E+00 -0. 84 32810. 0.1142E+01 -0. 85 26248. 0.1432E+01 -0. 86 19686. 0.2394E+01 -0. 87 13124. 0.9332E+01 -0. 88 6562. 0.4124E+01 -0. 89 0. -0.1259E+02 -0. CASE 11 V 15,000 ft/sec X = -20' 109 ROW NUMBER I KK ALTITUDE(FT.) DENSITY DOWNRANGE CROSSRANGE - 98430. -0. 54985+00 -0. 2 91868. -0.7211E+00 -0. 3 85306. -0.9481E+00 -0. 4 78744. -O.1243E+01 -0. 5 72182. -O.1660E+01 -0. 6 6562Q. -0.2198E+01 -0. 7 05,. -0.2922E+01 -0. 8 52496. -O.3879E+01 -0. 9 43934. -0.5129E+01 -0. 10 39372. -0.6779E+01 -0. 3280. -0.8879E+01 -0. 12 26248. -0.1111E+02 -0. 13 19686. _0.1357F+02 -0. 14 13124. -0.1626E+02 -0. 15 6562. -0.1761E+02 -0. 16 0. -0.9100E+01 -0. 1 CASE 15 V = 15,000 =-400 -110 ft/sec ROW NUMBER KK 2 AL! ITUUE (F T.) SPEED OF SOUND DOWNRANGE CRSSR ANGE 17 98430. -0.6674E-02 -0. 18 91868. -0.8749E-02 -0. 19 85306. -0.1147E-01 -0. 26' 78744. -0.1497F-01 -0. 21 72182. -0. 3293E-00 -0. 22 65620. -0.3326E6-00 -0. 23 59058. -0. 4290E-00 -0. -0. 5447 E+OO -0. 24 25 45934. -0. 6786E+00 -0. 26 3 937 2. -0. 1029E+01 -0. 27 32810m -0. 2419E+01 -0. 28 26248.0 -0.3704E+U1 -p. 19686. -0.1350E+02 -0. 13124. -0.9491E+01 -0. -0. 30 31 6562. -0.1979E+02 32 p. 0.7972E+OOU CASE 15 V= 15,000 T= ~J40 i40 ft/sec -0. ROU' KK A LTITUDOET) DOWNRANGE NUtER 3 DRAG COEFFICIENT CROSSRANGE 40874s" -0.2408E+02 -0. 34 11781. -0.5468E+02 -0. 35 5298 -0. 1760E+O2 -0. -0.5408E+01 -0. 36 0. CASE 15 V = 15,000 ft/sec = -40' 112 DOWNRANGE ROW NUMBER 5 KK DOWNRANGE ALTITUDE(FT.) WINC CROSSRANGE ~41 98430. 0.5101E-01 -0. 42 91868. 0.6524E-01 -0. 43 85306. 0.8334E-01 -0. 44 78744. 0.1057E-OC -0. 45 72182. 0.1348E-00 -0. 46 65620. 0.1725E-00 -0. 47 59058. 0.2214E-00 -0. 48 92496. 0.2845E-00 -0. 49 45934. 0.3642E-00 -0. 50 39372. 0.4658E-00 -0. 51 32810. 0.5998E+00 -0. 52 26248. 0.7692E+00 -00 53 19686. 0.9268E+00 -0. 54 13124. 0.1512E+01 -0. 55 65620 0.2448E+01 -0. 0.5366F+01 -0. 56 0. CASE 15 V = 15,000 r= -40' 113 ft/sec ROW NUMBER 6 KK AL TUD (FT. DOWNRANGE *430. 5 9 58 9168 CROSSRANGE WIND CROSSR&NGE -0. 0.492lf-Ol -0. 0.62949-01 -0. 0.8015E-01 6 874. -0. 0.1027E-00 61 S 2182 -0. 0.1307E-00 62 65620. -0. 0. 1675E-00 63 59058. -0. 0.2138E-00 64 52496. -0. 0.2716E-00 65 45934. -0. 0.3470E-00 66 39372. -0. 0.4443E-00 67 32810. -0. 0.5714E+00 68 26248. -0. 0.7244E+00 0. 0*9558E+00 -0. 0.1458E+01 -0 0.2641E01 -0. 0.4777E+01 6 7013124 71 6562 72 0 CASE 15 V 15,000 ft/sec = -40 114 ROW NUMBER 7 KK ALTITUDE(FT.) VERTICAL COWNRANGE CROSSRANGE 73 98430. 0.4734F-01 -0. 74 91868. 0.6001E-01 -0. 75 85306. 0.7587E-01 -0. 76 78744. 0.9498E-01 -0. 77 72182. 0.1221E-O0 -0. 78 65620. u.1528E-00 -0. 79 59058 0.1920E-00 -0. 80 52496. 0.2402E-C0 -0. 81 45934. O.2971E-00 -0. 82 39372. 0.3649F-00 -3. 83 32810. 0.4576F-00 -0. 84 26248. O.5626E+00 -0. 85 19686. 0.7572E+00 -0. 86 13124. 0.1104E+01 -0. 87 6562. 0.1973E+I1 -0. 88 C. 0.3496E+01 -0. CASE 15 V = 15,000 ft/sec = -400 115 APPENDIX B METEOROLOGICAL DATA USED IN ANALYSIS The data here are reasonably self-explanatory. The RHOBAR are the mean values of density, in slugs per cubic foot, for 0 (2) 30 kilometers, and are read in ascending order. The ABAR are the mean values of the speed of sound in feet per second, for the same altitudes. The UBAR are the mean values of the west wind in feet per -second and the VBAR are the means of the south wind. The standard deviations of density and speed-of-sound are given as fractions of the mean, while the winds are given in feet per second. The off diagonal submatrices (RHO A MATRIX, etc.) are the upper right hand members; the lower left hand members are omitted. I. .- e0o1E-Ow 0.1040*E-09 0.16116E-01 0.1890RE-02 RHOBAR 0.10161E-01 0.75660E-03 0.54tt4E-03 0.39vtE-03 UE4IiE-03 0. O'tSE-03 0.lS*44E-03 0.11264E-03 O.W3W3OE-04 O.6Z46SE-04 0.46959E-04 U.54',tLE-4 0.98136E+03 0.994feE+03 0.10141f+64 '. ABAR I 0.104i3E+04 O.10654E+04 0.1060?E+04 0.10953E+94 0.11093E+04 0.1122SE+04 0.115'vf+f 1t,',tE+0t O.Z67?E+2 0.-2Ot3E+02 0.2666?E+02 UBAR 0.32821E+02 0.3837E+02 0.4eESE+02 0.444k4E+G0 0.4bZ60E+02 0.48055E+0Z 0.49651E+02 0.51646E+02 0.53442E+02 0.5523E+02 0.57033E+02 0.5682vE+0 3.346iE+01 0.11841E+O1 0.144&ZE+01 0.12344E+01 0.85312E+00 -0.11566E+01 -0.392o7E+o1 -0.5779(E+01 -U.'3O04E+01 -0.44813E+01 -0.11332E+02 -0.13183E+02 -0.15034E+02 -0.16885E+02 -0.16735E+02 -0.20586E+02 -1O3U SE+04 VBAR 117 RHO RHO STANDARD DEVIATIONS 0.30001E-01 0.1149tE-0i 0.15883E-01 0.14401E-01 0.19437E-01 0.55142E-01 0.1111&E-00 0.12693E-00 1.12t06E-00 0.11766E-00 0.*.177E-01 0.66337E-01 0.34335E-01 0.45050E-01 0.10044E-00 0.17101E-eG RHO RHO MATRIx 1.0000 0.4034 0.b62 0.S1S4 0.4456-0.2206-0.ZS21-O.2972-0.3113-0.3149-0.3205-O.3245-0.2605 0.1368 0.2460 0.2720 0.$034 1.0000 0.6937 0.5937 0.1?15-0.3121-0.3363-0.3392-0.3464-0.3447-0.3450-0.3448-0.2758 0.15C0 0.2667 0.2913 0.f901 0.-437 1.0000 0.7637 0.1795-0.3243-0.3426-0.3339-0.3339-0.3252-0.311-0.3039-0.2044 0.1974 0.2756 0.2092 0.5154 0.5 9 37 0.7637 1.0000 0.6915 0.0126-0.1690-0.2082-0.2311-0.2317-0.2257-0.1948-0.0263 0.3142 0.3237 0.31(4 0.2456 0.1715 0.1795 0.6925 1.0000 0.4172 0.1141 0.0263-0.0159-0.0329-0.0370-0.0097 0.1403 0.2835 0.2300 0.2103 -O.Z200-0.3121-0.3243 0.0126 0.4172 1.0000 0.9355 0.8924 0.0642 0.8454 0.8291 0.8041 0.5933-0.4297- 0.6500-0.7035 -0.2021-0.3363-0.3426-0.1698 0.1141 0.9355 1.0000 0.9910 0.9776 0.9644 0.9469 0.9040 0.5916-0.6232- 0.6515-0.0900 -0.2972-0.3392-0.3339-0.202 0.0283 0.8924 0.9910 1.0000 0.9960 0.9894 0.9771 0.9301 0.6215-0.6409- 0.8833-0.9268 -0.3113-0.3464-0.3339-0.2311-0.0159 0.8642 0.9776 0.9960 1.0000 0.9974 0.9094 0.9561 0.6502-0.6204-0.0841-0.9321 -0.3149-0.3447-0.3252-0.2317-0.0329 0.8454 0.9644 0.9894 0.9974 1.0000 0.9968 0.9717 0.6071-0.5971-0.8694-0.9235 -0.3205-0.3450-0.3101-0.2257-0.0370 0.8291 0.9469 0.9771 0.9094 0.9968 1.0000 0.9870 0.7381-0.5412-0.8364-0.8992 -0.3245-0.3440-0.3039-0.1940-0.0097 0.0041 0.9040 0.9381 0.9561 0.9717 0.9870 1.0000 0.8362-0.4022-0.7413-0.6218 -0.2665-0.2752-0.2044-0.0283 0.1403 0.5933 0.5916 0.6215 0.6502 0.6871 0.7381 0.8362 1.0000 0.1651-0.2534-0.3773 0.1360 0.1560 0.1974 0.3142 0.2835-0.4297-0.6232-0.6409-0.6204-0.5971-0.5412-0.4022 0.1651 1.0000 0.9121 U.S30t 0.2460 0.2667 0.2756 0.3237 0.2300-0.6506-0.8515-0.8833-0.0841-0.8694-0.8364-0.7413-0.2534 0.9121 1.0000 0.9914 0.2720 0.2913 0.2892 0.3104 0.2103-0.7035-0.8908-0.9268-0.9321-0.9235-0.8992-0.8218-0.3773 0.8506 0.9914 1.0000 118 ilUUUl I 00001 0000 *I 6666'0 V666,0 996610 611 i66*0 o9,66 0 6096'0 S66610 a *O n nono0 Y nno00 -1666 *0 0666 *0 Oi660 T IFf60; 00 tl6 6 -0 6666 0 0000 1 000011 0000 1 0- 90CI 10- vi I .0- ?6CzO~Z- T 966610 C666 *0 Z96610 ZS66'0 4666 0 L666'0 6666 0 0000 1 0000 T 6666 0 9666*0 L96610 0966 *0 0S96*0 99SG60 v666 0 466610 9666 0 6666 0 0000 266610 966*0 IRS66 0 0666 *0 S666*0 9666*0 1 661 0 C66610 0i66*0 6906 *0 1196*0 6666 0 0000*1 L 666,0 1966 *0 S69610 OL6610 2966 *0 .1966 *0 C666 0 166610 0000 6)66*0 1 266610 V266.0 PI010-60-P9-?TS0-29wZ0-9vrsz0- caL66 0 6006 0 I Z96*0 96i6*0 VV6610 zr6(6*0 0966'0 OL6610 196610 2666 0 00001 Z2S66 V966 0 VS06 *0 0'36.0 699610 S69610 VZ66,0 V966*0 0000 1 9OS610 119610 VV96*0 6996*0 C16*0 0P06*0 0000 * U.96 0 LV 6*0 ;4s6l0 IreO SZ01*0 6119*0 V?9vP0 000011 VZV610 CZ9*0 i0evP0 clos,0 0?(' * V~vP*0 000011 c~iiC0 cios' toot'n07-0 x1oIv" Or-QG0010-34C660 0Go-3Z;?O 00-39 32iiiV0 tO-39M310 v v OUV~O 20-3OO6W60 10-310A;1'0 IWNOIIVIA3a 10-320tol'a tits2alO 00-3k;04910 00o-MOI?0 v aMYONvis v 000011 066610 SW6610 .1296o OZ1 6VEV0 sactl0 i9z00 SG0C*0-Vlsc0o-Si t 0-000C.0-0112Z0-190l.0-68zt10- 0666 *0 0000* I Z966 *a 106610 699610 94,06*0 9V9110 921vP0 911010 ILWPO 616 0 ZITZ0 106610 IL966 0 0000* I 910010 TV29*0 9001O 296f 0 0000, 1 L966*0 IZ 6*O iLSG*0 699610 006.0 ZCG66*0 0000 T 9L06*0 G60 60 9LS6*0 4,S*O .3#91 0 91090 ilt10 HMO6 *C060 6190 stzcl0 0000 1 9V9610 6061*0 *cov'0 0891*0 VG60* 9v96*0 00001t C62610 9S69*0 ,IIV0 q0010 SVT110 2621.0 OVT.0 ess0*0 lEcc0 0061*0 sleclo GVi Ivs *0616910 610910 606410 c626*0 0000*1 6Z160o S Ca10 *~ 0 '32LVI 3IL0*0 90C 1 0 zitZlo 6M 1 0 I Ivw0 vitv,0 scziv0 CV6*0 0000 1 660V 0 91690 6Z1610 0000*1 CZV6 0 0-900 0I'ttvt.0 90 TV900 ILOS6* 0000 I'O 90ce0 2099*0 600 261610 0000 IR6O 6066.0 0000* 1 669010 so,gloeco V61600 l MiloJ2 SC96*0 0000 1 0216S *0 016#10 00001 OCV*0 006110 s61 0 66avl0 11C,0 x1iw n m 90432112660 80436*lsW0 I043s it0l 20.3900VO IWIIWIAIO ONYONWvis A n r,69010 296900 * 0o-0 0-C0-02ILVI 20432tolvP0 * 009C0 6 Geclo OV1910 V9Z00 apv0l 1P29*0 909@*0 911690 61E'0o-0100-16010-96 Z960 0 vosel0 actfl0 106 c 0830-16,20-0080-~t6C 10*3fs'3iV0 80#301tst 0 V09tC0 olf~t~o t0o 0 0000,1 ?0*31#svtp0 10*31*ttt V0*300%ft*0 20. 10T0W P0'3?1TC 0 "4l3tsl 0 I 0.45972E*02 0.32675E+02 V V STANDARD DEVIATIONS 0.41981E+02 0.50663E+02 0.49194E+02 0.4359$E+02 0.59014E+02 0.30450E*04 0.4206?E+02 0.46947E+02 0.5?939E+02 0.68213E+02 0.90829E+02 0.10272,E+03 - O.90493E+01 1.%)00 0.29 0.3905 0.5sst 0.3?t0 o.?d7 0.79272E+02 V V MATRIx 0.2257 0.1686 0.0662 0.0013 -0.0656-0.1117-0.1427-0.1640-0.1790-0.1901 0. 29%2 1.0000 0.9007 0.9849 0.9255 0.9103 0.6678 0.0125 0.6646 0.4618 0.2715 0.1234 0.0149-0.064f-0.1240-0.lV4 0. 3905 0-900' 1.0000 0.9434 0.8767 0.8523 0.8006 0.744? 0.6035 0.4125 0.2350 0.0976-0.0029-0.0763-0.1310-0.1728 0. 3365 0.9649 0.9434 1.0000 0.9657 0.9463 0.8*55 0.623? 0.6675 0.4563 0.2599 0.1079-0.0032-0.0844-0.1449-0.1911 0. 3260 0.9255 0.8767 0.9657 1.0000 0.9800 0.8856 0.8169 0.6574 0.4423 0. 24 39 0.0909-0.0206-0.1019-0.1(24-0.2085 0. 2872 0.9103 0.8523 0.9463 0.9800 1.0000 0.9544 0.8871 0.7181 0.4899 0.2781 0.1141-0.0057-0.0932-0.1584-0.2083 0. 2257 0.8678 0.8006 0.8855 0.8858 0.9544 1.0000 0.9569 0.8081 0.5897 0.3789 0.2120 0.0082-0.0031-0.0717-0.1243 0. 1686 0.8125 0.7447 0.8237 0.8189 0.8871 0.9569 1.0000 0.9443 0.7988 0.6312 0.4865 0.373E 0.2873 0.2209 0.1t90 0.0062 0.6648 0.6035 0.6675 0.6574 0.7181 0.8081 0.9443 1.0000 0.9523 0.8513 0.7470 0.6580 0.5865 0.5296 0.4840 0. 0013 0.4618 0.4125 0.4563 0.4423 0.4899 0.5897 0.7980 0.9523 1.0000 0.9708 0.9143 0.8565 0.8058 0.7633 0.7280 -0.0656 0.2715 0.2350 0.2599 0.2439 0.2781 0.3789 0.6312 0.8513 0.9708 1.0000 0.9847 0.9553 0.9243 0.8959 0.8712 -0. 1117 0.1234 0.0976 0.1079 0.0909 0.1141 0.2120 0.4865 0.7470 0.9143 0.9847 1.0000 0.9922 0.9766 0.9596 0.9433 -0. 1427 0.0149-0.0029-0.0032-0.0206-0.0057 0.0882 0.3736 0.6580 0.8565 0.9553 0.9922 1.0000 0.9958 0.9672 0.9774 -0. 1640-0.0646-0.0/63-0.0844-0.1019-0.0932-0.0031 0.2873 0.5865 0.8058 0.9243 0.9766 0.9958 1.oou L.994 .994( -0. 1790-0.1240-0.1310-0.1449-0.1624-0.1584-0.0717 0.2209 0.5296 0.7633 0.8959 0.9596 0.9S72 0.9976 1.0000 0.998( -0. 1901-0.1694-0.1720-0.1911-0.2085-0.2003-0.1243 0.1690 0.4840 0.7280 0.8712 0.9433 0.9774 0.9926 0.998f 1.0000 121 C946*0 0i0 V946'0 S 660 49160 vs~s*0 Lfve0 6t60~ 2V60~ SVG* 04610 VOLVO 9is60 0 LG6 999610 v60* GVVG*0 ESVS0 45VG0 lseP6 b00o~-0~o0-640,0.09 O-0OzOl0- SO 660 26*0 osl;aa * 1000 & T0*0-6*0T*o-!#11 *0- iv*O 994clo *VV*O 6tI00 OOM0- V09110 4.4.6M0 LSVC0 POOPO C6CO 166Z *0 0116*0 6@9f*0 69cc60 0'96z0 0S0OC 624cl0 Z9ZC*0 ?041,0 Z9:Iv0 6i2C0 sitlZVISI 061011vtO 6Zcl'0 sfzv0 60o 115,0 0CS001 soo 190060* SM10 169C0 s9zc60 w*6' s6scl0 l000 91VE*0 266P0 lwo 06* ci 1'3' 0169*0 0C660 A0IC0 It6Pl 9696000960 zt"*0 )99210 V192Va avezO'0 619210 eoiz2a 66120 t"4'0 vsV210 IPLI '0 ,~62o-P612o-6o~o'0-9e61'o-?60?'o I 1' 0 0062' 0 066210 to0061 0 6106*0 fc0670 *'40sl 0616 0 tvo s11670 P616 '0 615670 42wo qf616 ' 41 160 0ott60 0d6If '0 61060 set010 cl1060 EMIG' 1062.0 616810 lIPiD 61P6'0-6616'0-1006'0-6#ls '0-16960v OWN Ilujyw 6~1 00 olotl0 sea060 F IZ21*0 vsvI ww-0 6911-0 0~o zSI*o olclo S1o1* 01*~0 L00 4TV0.0 LLiOO o9So* 9910-0 eo0 V90 -41096.0o" - 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A0 0 st *0lg -911*n 9t 0-01 -Otv10 Mt*0 sit -% t W )1t*0 ,P'a ~ 1iZl GCO ieO~o-;tO~O-v~o-tO 0-vv iO0-6O-OO-ZOO-6OO0-iOO-LOlIOO10-Z'OO S600ct~-~l-SODOL*-GO00E*-ooovzl C400O-6i0,- Po*OO-io IO-S6EOO -ZAOO-SfaoO *@90*0 ac00o-*00ol-64100-100o*-000 ir*Oo-tOTO'o-zsOO*o-cTOOa io 110CSa* 90010 960010 "Volo 601*0 d.00 v6colo ZV9O00 CoTOo0 vzzaaO tefo *9O 6fO -9v*09v @10*0 ascolo 9801o 161010 V90010 1511*Q LV911O tilo -CO -LVOOMwOv' -2o020 vo~O O 9090*0 0690*0 46vPo it0W0- LVTo1o izcWo ocoTo e6010 C19100 L6101- Milo L16O STWIO zcGO*O 1910*0 m*C6tOo 900 *#OOa 6490* OOO01-vtOOlo-VOOO ssOO~O szTOo 9120o0 9clO LVO*O 9vO'O-szO'O-zoO'o *ooo ozOOlo4OOOO-OOOO01 620010 990*0 9zUvoo IVSOO 9920*0 66OO0 80 2 vio'o ZSo'o CZZO*o VC00o ;zzO* GWO-ltoO*O-vsOo ssOlO t9sOlO IscO* 9OO0 cSOO-9OO-TOO-96sO~o - TO* -vPO'O-i~zO O-tO*O-Z,OO tOlO CG6T00 szzolO 2ZOO ZZOO ;OO-OZZO-96oo-pzoo-eegoa szolo TZCoIO *icOo Vecoo IS10* COO~O-O#wo-oolO-6VOOO-OOO1-zgOO~O-g01o- AOOO0-9900O-960O-t6zo~o-OCSOO-tzO~O-oco~O-i#sOO-,tso~o ~ ztvolo i),O iV11 OZW:O ;e;:o 916110 tifto 199110 Itell Mo I -L vtC0I-vs 0-6@90 -6vv00-6OlO* -0900,0-6060 1 vTTTa V99010 *tolo osso'o-sc1 *o 90C0-iv 6CO0 9ootsl09t,0 IO* tcO1O-9vfI*O- C61'o 9vi100 sit00 149TO %9110 9641,0 verl'0 OittO f0L00o VZ000 tto*014 OLelo 411210 VVII1 V6iSPO 99610 888110 et;0o XIUIVN -180 zl -40, - t,09v,0 oe 9Ia 101l0O6OSP8-dI-G09*~-tl-~ A 0MW A 0,0640 0.312i U MATRIX 0.3504 0.326? 0.2*72 0.2914 0.2920 0.2597 0.1705 0.0001 0.0022-0.0493-0.0630-0.1059-0.1221-0.1340 01840 0.1003 0.1450 0.1176 0.0*93 0.0722 0.02?S-0.01 6 5-0.0466-0.0649-0.0760-O.0S31-0.0660-0.owi4 -0.et*s-0.0043 0.0244-0.0099-0.031-0.070.1006-0.105-0.1010-0.0792-0.056-0.039-0.027-0.0191-0.0127-U.U07$ -0-1642 0.02U1 0.0536 0.0075-0.0376-0.0608-0.0965-0.1029-0.0946-0.0729-0.0511-0.047-0.0232-0.0149-0.0086-0U.04? 0.0479 0.1143 0.1427 0.0960 0.0272 0.0063 0.0126-0.0226-0.0619-0.0862-0.0994-0.1029-0.1036-0.1032-0.1024-0.101 0.0347 0.0695 0.0917 0.1064 -0.0439-0.22t9-0.2195-0.2174-0.1849-0.148-0.1944-0.1606-0.0942-0.0200 0.11E7 0.1241 -0-1087-0.2754-0.2736-0.2677-0.2231-0.2269-0.2430-0.2020-0.1200-0.0280 0.0402 0.0036 0.1113 0.1298 0.1427 0.1521 -0.1282-0.2606-0.2769-0.2740-0.2322-02389-0.2554-0.2111-0.1238-0.026 0.0456 0.0913 0.1204 0.1397 0.1532 0. 131 -0.1370-0.2825-0.2780-0.2764-0.2359-0.2440-0.2607-0.2149-0.1253-0.0254 0.0481 0.0947 0.1244 0.1441 0. 1 579 0.1679 -0.1423-0.2835-0.2785-0.2778-0.2381-0.2469-0.2637-0.2171-0.1261-0.0249 0.0495 0.0968 0.1267 0.1467 0. 1606 0.1707 -0.1459--0.2842-0.2789-0.2787-0.2395-0.2489-0.2657-0.2186-0.1266-0.0245 0.0505 0.0981 0.1283 0.1484 0.1624 0.1726 -0. 1485-0.2647-0.2792-0.2794-0.2406-0.2504-0.2673-0.2197-0.1271-0.0243 0.0513 0.0991 0.1295 0.1497 0.1638 0.1741 -0.1507-0.2651-0.2795-0.2799-0.2414-0.2515-0.2685-0.2206-0.1274-0.0241 0.0518 0.0999 0.1305 0.1507 0.1649 0.1752 -0. 1524-O.2855-0.2798-0.2804-0.2422-0.2525-0.2695-0.2213-0.1277-0.0239 0.0523 0.1006 0.1313 0.1516 0.1658 0.1761 -0.1539-0.2856-0.2000-0.2808-0.2428-0.2534-0.2704-0.2219-0.1279-0.0238 0.0527 0.1012 0.1319 0.1523 0.1666 0.1769 -0.1552-0.2960-0.2802-0.2812-0.2433-0.2541-0.2712-0.2225-01282-0.0237 0.0531 0.1017 0.1325 0.1529 0.1672 0.177f 125 V MATRIX A 0.4330 0.1*20 0.1004 0.217S 0.1497 0.2324 0.1664 0.0955 0.0052-0.0791-0.1401-O.1792-0.2040-0.2200-0.230g-0.23$5 U-4'14 9.19%0 0.14'1 0.2135 0.4310 0.0s u.31to 0.0'20 0. te' 0.2941-0.0303 0 .0 0.1500 0.0962 0.0292-0.0377-0.077-0.120-0.1423-0.15tf-0.165-.1?5 0.1097 0.095j 0.0703 0.0lO5-0.0209-0.0657-0.10070.1215-0.1320.1373-0.157-0. 1408-0.1411 6 4 0-0.00?Z-O.OO92-0.0347-0.0655-0.1424-0.1921-0.2190-0.2256-0.2222-0.2155-0.?08(-0.l02Z-U.19Vf 0.2611-0.0522-0.0052-0.0330-0.0241-0.0404-0.0402-0.1426-0.1968-0.2510-0.2409-0.2593-0.2556-0.2272-0.2211-O.ZI57 -0.0529 0.0298 0.0235 0.0363 0.0453 0.0120-0.0275-0.0486-0.0673-0.0781-0.0813-0.0507-0.0787-0.0765-0.0?44-0.072f -0.0637 0.0353 0.0374 0.0409 0.0424 0.0102-0.0257-0.0354-0.0427-0.0452-0.0442-0.0418-0.0393-0.0371-0.0353-0.0357 -0.026 0.0250 0.0338 0.0302 -0.0474 0.027G--.0373-1.2436-0.0525-0.0570-0.0555-0.0507-0.0455-O.G4DE-D.0567-0.035t-O.0512 0.0203 0.0322 0.0254 0.0200-0.0152-0.0517-0.0601-0.0E33-0.0600-0.0534-0.0467-0.0410-0.03E4-0.032SO-.0299 -0.0442 0.01?C- 0.0312 0.0226 0.0160-0.0198-0.0563-0.0644-0.0669-0.0626-0.0550-0.0475-0.0412-G.0362-G.O3Z3-G.GZ91 8-0.0593-0.067 3-0.069 3 -0.0 6 4 2-0.05 6 0-0.0480-0.C413-0.0360-0.0319-0.028 0.0207 0 .01 -0.0405 0.0145 0.0302 0.0194 0 . 0 1 1 4 -0.(250-0.0615-0.0693-0.0709-0.065 -0.0421 0.0158 0.0306 3 3 -0.0 2 2 4 -0.0567-0.0483-0.0414-0.0359-0.031(-0.0282 -0.0392 0.0136 0.0299 0.0184 0.0100-0.0266-0.0631-0.0708-0.0722-0.0663-0.0572-0.0485-0.0414-0.0358-0.0313-0.GZ78 -0.0352 0.0128 0.0297 0.0176 0.0088-0.0279-0.0644-0.0720-0.0732-0.0669-0.0576-0.0487-0.0414-0.0356-0.0311-0.027C -0.0374 0.0122 0.0295 0.0170 0.0079-0.0290-.0655-0.0730-0.0740-0.0675-0.0579-0.0488-0.0414-0.0355-0.0309-0.0273 -0.0366 0.0117 0.0294 0.0165 0.0071-0.0299-0.0664-0.0738-0.0746-0.0679-00581-0.0489-0.0413-0.0354-0.035O-0.0271 126 4490*0 0160*0 C960.0 oz0t0 2011O tsso00 L69010 L Zt 19920a 4 00* 0-9&0010 61000 TGT100 T1l#10- 941t.0 6T110 Id. 1 10 V660,0 S6010 0201*0 9601*0 SLIVO OUT *0061110 LL1010 TU60 9cO*0 zft100 60ct10100*0-C90010 OC90*o 119O 4C60,0 L0OOVO 060110 eaIVO 6czT*0 vvm0 Z01 0 91 000 0 EO0 0 100 9sTT*0- ss00*0 TO00*O s6i0*0 SVP00O L060,0 Z96010 2LT010 L11*0 svzl SSooo CS1oo oVSeoo- S900*0 1 0 00 0 4C10*0 06iO SS9010 LC 60 SC01*0 SVITIO 6V2110 1 SC11*0 *0 WcO'o oz90oo- vamo Z10*0 14tooo 260 *0 zcoo SiZ~Oo zs000 *Z1010 9ZTO00- 0O 90*0 11U0*0 TZ10 61100 CIT100 0 900 2crala 06P00 Z99010 S9900 Z1Li00 06010 L901 0 691110 V911*0 2vs0*0 O140*0 4990*0 9610O0 VP0*0 CS60,0 6100 061110 V010*0 )C.0* r Z200 11C00 92000 zVT010 610010 1191'0 gis0*0 VS1010 916010 C66010 696010 Z2i0*0 Z00o~-6 200o-6910o-1Z0*0-9100*0-i0100 I'M *0 98v0*0 vT0*0 *210 6zvz *0 Z990 *0 1 9010 1960*0 0110*0 00ol-cso00-c0so0-6sv000-Pvf0oo-c6z00o-9c1000-oi0 1210o 110oo-4.da* Z9010 M9010 -9P100-C9000 0900-C6SO00-300ol-000ol-c1so00-c0000-2 TV20*0 VLV010 ZZ90*0 9vc 00 gsc00 6 10*0 as6010 tesololsesolo-gosolo-josolo-lisolo-ossolo-tevolo-6scolo-sololo-stoo*o-tszolo tC010 tsto0o c9co0O 90100a I*O*1 A zso*o-cccoo-lvoo*o-C90*0 os00~0- vfz*O-eOIO*o-cv9*? . v49010-i$4010-01LOIO-ItiO,0-6910*0-voio*o-oiio*o-oego*o- XIVW n 128 REFERENCES 1. 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