Chapter 7 Geometric Corrections
7.1 gcpmatch
 Command name
gcpmatch [-options] Nnyymddhh …
 Options
-O <dir>
-P <dir>
-R <dir>
-C <dir>
-D <dir>
-G <dir>
-B <dir>
-M <dir>
specify the directory holding the GCP matching image file
specify the directory holding the parameter file
specify the directory holding the pre-data file
specify the directory holding the control file
specify the directory holding the coastline data file
specify the directory holding the GCP position data file
specify the directory holding the orbital element file
specify the output directory to store the results of the GCP matching
 Environment variables
PANDAWORKDIR
file)
PANDAIMAGEDIR
PANDACOASTDIR
PANDAGCPDIR
(parameter file, control file, orbital element file, pre-data file, and GCP matching result
(GCP matching image file)
(coastline data file)
(GCP position data file)
 Descriptions
GCP matching is carried out.
 Reference directory
Input/output files get access to the files under the directory specified by the options. When no options are specified,
files in the directory specified by the environmental variables get accessed instead. When neither option nor
environment variable is specified, the files in the current directory are accessed.
 Input files
Nnyymddhh.pam
Nnyymddhh.cnt
Nnyymddhh.pre
Nnyymddhh.obt
Nnyymddhh.GCP
NnyymddhhHGCP
coastal.gcp
gcpll.fil
parameter file
control file
pre-data file
orbital elements file
GCP matching image file
GCP matching image header file
coastline data file
GCP position data file
 Output files
Nnyymddhh.gcp
file contains the results of the GCP matching
 Flow chart
Start - Select blocks that contain GCPs under consideration - Extract GCPs under consideration from each block Select matching area centered around each GCP - Remove noise and clouds from the area to be matched (create
masks) - Extract coastlines from the matching area - Transfer coastlines for matching onto the original image - Select
GCPs for each block - End.
 Error messages
7.2 getorbit
 Command name
getorbit [-options] Nnyymddhh …
 Options
-A <dir>
-O <dir>
specify the directory storing the orbital information database file
specify the output directory to store the orbital element file
 Environment variables
PANDAWORKDIR
PANDAORBITDIR
(orbital element file)
(orbital information database file)
 Descriptions
Search the orbital information database file for the orbital elements computed for some specified time and write to
the orbital element file.
 Reference directory
Input/output files get access to the files under the directory specified by the options. When no options are specified,
files in the directory specified by the environmental variables get accessed instead. When neither option nor
environment variable is specified, the files in the current directory are accessed.
 Input files
orbit.fil
orbital information database file
 Output files
Nnyymddhh.obt
orbital element file
 Error messages
7.3 bandle5
 Descriptions
Estimate the position and attitude of the satellite using collinearity conditions applied in the photogrametry,
 Program structures
MAIN ---
ORIENT --|
---
HEADER
READIN
(Subroutines and their descriptions)
ANGL
compute coefficients of the orientation element polynomials
BTWB
compute TW
CHLSKY
solve *** equations using Cholesky method and compute errors in orientation elements COEFOE
evaluate the coefficient matrix (, , F) of the collinearity equations
COROUT
print out a table of the orientation element correlation
CORREL
compute correlation coefficients of the orientation elements
DEGDMS
convert from degrees to (degrees, minutes, and seconds)
DMSDEG
convert from (degrees, minutes, and seconds) to degrees
DXYZ
compute measurement errors in the ground coordinates
ECRBLH
versa
HEADER
INVERT
INVRT3
MJDMK
MTIME
NORMAL
OBJVXY
ORBIT
ORIENT
ORIMAT
ORTHOG
OUTPUT
PANDQ
READIN
SORTNG
TRACE
transform the earth fixed coordinate system into the longitude latitude coordinate system and vice
read in the program title and control data for the orientation computation
compute a inverse matrix of the coefficient matrix in the *** equation
compute a inverse of 3 x 3 matrix
compute Modified Julian Date from the pre-data
compute ephemeris time
Form a coefficient matrix from ***
Print out the residual of the measured points on the image and the ground and compute***
read in the orbital information
compute orientations
compute a orientation matrix for each line
compute coefficients of polynomials for all the image points
output the title for the printout
compute TW and (TW)  (TW)-1
read in the ground control points, image point data, and orbital information etc.
sort the image points according to their numbers
create a ground coordinate file
 Input data limits
Maximum number of images
Maximum number of image data
Maximum number of ground control points
Maximum unknown variables
1 scene
100
100
100
 Input files
Control file for orientation computation
Control file for unknown variables
Temporary file
-- Default values included
Ground Control point file
Image point data file
Orbital element file
Pre-data file
Image header file
Control file
Parameter file
Scheduling file
-- Automatically generated
 Output files
Final orientation element file
Ground coordinate file (per 16 lines, 32 pixels)
 Input parameters and file descriptions
We will describe each of the input files (underlined are default values) in this section. Note that when you use the
GCPs you obtained, you would need to modify the ground control point file and image point data file, however, it is
generally not necessary to modify the rest of the files.
(A) Contents of the control file for orientation computation
<Input parameters>
1st data:
Orientation computation title
TITLE (format; A70)
2nd data:
Number of iterations for the orientation computation (MIN, MAX) and types of the orientation
elements.
MINITR
Minimum iteration number which is in general 3.
MAXITR
Maximum iteration number which is in general 12.
NPAR
Number of orientation elements (fixed at 7).
3rd data:
Control parameter data for the orientation computation and convergence limit and ***
KONTRL, EPSIT, EPSEP (format;
)
<KONTRL>;
Control parameter for the orientation computation.
KONTRL(1)
Set the order of unknowns in the orientation elements (fixed at 3)??*** (1 =
constant, 2 = 1st, 3 = 2nd, …)
KONTRL(2)
Spare.
KONTRL(3)
Spare.
KONTRL(4)
Orbital element setting up codes
= 0 indicating 1day data is used to interpolate; =1 indicating 2 days of data.
KONTRL(5)
Residual testing codes for the orientation elements entered
= 0 indicates no residual testing; = 1 indicates testing.
KONTRL(6) - (11)
Spares.
KONTRL(12) Coefficient output codes for normal equations
= 0 indicates no output; = 1 indicates output.
KONTRL(13) Output codes for the iteration of orientation computation (1 - 5).
The larger the number, the more precise the output content becomes.
KONTRL(14) Output codes for the initial estimate of the ground coordinates
= 0 indicates no output; = 1 indicates output.
KONTRL(15) Output codes for divergence, ***matrices
= 0 indicates no output; = 1 indicates output.
KONTRL(16)
*** the orientation elements
= 0 indicates no action; = 1 computes the standard deviation of the orientation
KONTRL(17)
Output codes for the final results of GCP residuals computed for the image and
elements.
the ground
= 0 indicates no output; = 1 indicates output.
KONTRL(18)
*** the ground coordinates
= 0 indicates no output; = 1 computes the standard deviation about the control
points; = 2 computes the standard deviation about all the measured points.
<EPSIT>;
<EPSEP>;
4th data:
KONTRL(19)
Output codes for correlation table about the orientation elements
= 0 indicates no output; = 1 indicates output.
KONTRL(20)
Correction code for the ground coordinates (fixed at 0)
= 0 indicates no correction (when they are all control points).
Convergence limit for the iterative computation of the unit weight
< = EPSIT then we assume the convergence.
Normally, EPSIT = 0.00001.
Maximum value ***
Normally, EPSET = 0.100 (unit mm), EPSET = 5.000 (unit pixel).
Convergence limit for each of the orientation elements PLMT (format; 9F8.0).
PLMT (1)
Convergence limit given to a (=0.001) unit km
PLMT (2)
Convergence limit given to e (=0.000001) dimensionless
PLMT (3)
Convergence limit given to M (=0.000001) unit radian
PLMT (4)
PLMT (5)
PLMT (6)
PLMT (6)
PLMT (8)
PLMT (9)
5th data:
Convergence limit given to  (=0.000001) unit radian
Convergence limit given to i (=0.000001) unit radian
Convergence limit given to w (=0.001) unit radian
Convergence limit given to  (=0.001) unit radian
Convergence limit given to  (=0.001) unit radian – never been used
Convergence limit given to  (=0.001) unit radian –never been used
Standard deviation of computational errors.
RERRIC
Standard deviation of measurement errors about image point data (about 1 pixel
~ 1.5 pixel).
RERRXY
RERRZ
Standard deviation of ground coordinate (X, Y) measurement errors.
Relative to the topographical map scale used in the measurement
Standard deviation of ground coordinate (Z) measurement errors
Relative to the interval of contour lines on a topographical map used in the
measurement
(B) Descriptions of the unknown variable control file
<Input parameters and data>
1st data: Calibration code for orientation elements used in orientation computations.
Set the order of unknowns in the orientation elements (this has precedence over KONTRL(1)).
2nd data: Calibration code used in the orientation computation of orientation elements.
Number of unknowns.
Calibration code used in the orientation computation of the orientation element, a.
Will be specified in the order of constant, first order, second order, and third order.
= 0 no calibration (use an initially estimated value); = 1 do calibration (set orientation elements to
be unknowns)
IOBJ (6) – (9)
IOBJ (10) – (13)
IOBJ (14) – (17)
IOBJ (18) – (21)
IOBJ (22) – (25)
IOBJ (26) – (29)
IOBJ (30) – (33)
IOBJ (34) – (37)
Calibration code for the orientation element e
Calibration code for the orientation element M.
Calibration code for the orientation element .
Calibration code for the orientation element i.
Calibration code for the orientation element w.
Calibration code for the orientation element .
Calibration code for the orientation element .
Calibration code for the orientation element .
(C) Descriptions of the ground control point file
<Input parameters and data>
1st data:
Parameter code for the coordinate transformation of the ground coordinated values.
= 0 no coordinate transformations; = 1 Transform the latitude longitude coordinate system to the
earth fixed coordinate system. Orientation computation is carried out using the earth fixed coordinate system.
When ISYS = 1, the following parameters must be specified.
JCODE
IES
Earth fixed coordinate system code
Earth oblateness code (refer to the table below)
Table Earth oblateness code list
2nd data:
JPN
JCD
Input of the coordinate of the ground control points and weights
Ground control point names
Control point codes
Control point coordinates
Control point weights
(D) Descriptions of the image point data file
<Input parameters and data>
1st data:
Orbit number (fixed at 1)
2nd data:
Image point data
(E) Control file data required
IMAGEDIR:
directory where the image data is stored
GEODIR:
directory that contains geofiles
(F) Parameter file data required
GCP: use of GCPs
= 0;
do not use GCPs
= 1;
use GCPs
(G) Scheduling file data required
Rsmpl4: to specify the image data header file
(H) Header file data required
LINE: total number of lines
LSMP: information about the clipping direction
PSMP: information about the pixel direction
 Output file descriptions
(A) Contents of the final orientation element file
1st data:
2nd - 9th data
10th data:
11th data:
12th data
(B) Ground coordinate files
Output the ground coordinate and the sun position (latitude, longitude, sun elevation angle, and sun azimuth angle, in
this order) corresponding to each pixel of the original image ***every 16 lines *** 32 pixels***
Hence, the 16th line corresponds to the 1st line of actual image. All the units are in degrees.
 How to read the output
A section of the final results of the orientation is given below.
 Error messages
(1)
(2)
(3)
7.4 rsmpl4
 Descriptions
Create an geometrically corrected image using the results of orientation computation. Here the nearest neighbor
interpolation method is used.
 Program structures
(Subroutines and their descriptions)
AREA2
BILIN
BIPIN
CALUV
DMSDEG
GEOXYZ
system
IMGOT
MERCAT
system
MSHPRT
ORIMAT
PARAIN
POLAR
system
POLAR2
PXSIZE
RECIMG
SOLAR
TRANS
Find the initial estimate for the image coordinate corresponding to the output coordinate
Read in image data (BIL format)
Read in image data (BIP format)
Find the original image coordinate corresponding to the output coordinate
Conversion from (degrees, minutes and seconds) to degrees
Transformation between the earth fixed coordinate system and the latitude longitude coordinate
Output corrected images
Transformation between the Mercator coordinate system and the latitude longitude coordinate
Display the address for the input image corresponding to the mapping area
Compute the orientation matrix
Read input data
Transformation between the Polar Stereo coordinate system and the latitude longitude coordinate
Resampling processing using the Polar Stereo coordinate system
Compute line and pixel numbers corresponding to the output pixel size
Create a geometrically corrected image using ***image point grid data***
Compute the sun elevation angle
Compute the ground coordinate values corresponding to the ***unknown points***
 Input files
Final orientation element file
Ground coordinate file
Image data file
Image header file
Pre-data file
Control file
Parameter file
Scheduling file
 Output files
Image file with geometric corrections
Image header file
 Descriptions of the input parameter and input file
(A) Control file data required
IMAGEDIR:
directory holding the image data
GEODIR:
directory holding the geofiles
(B) Parameter file data required
GEOLIST:
channel number for geometric corrections
BGVAL:
padding values for the missing image area
MAP:
output coordinate system
MITYPE:
type of mapping area specifications
PTYPE:
mapping area
OFLN:
***longitude***
NSID:
the northern or southern hemisphere (for the Polar Stereo projection only)
(C) Scheduling file data required
rsmp14:
specify the image file identifier before and after the correction
 Output file descriptions
Two kinds of information (pixel number and the sun elevation angle), in addition to the channel data specified in the
geolist, will always be added to the image file with geometric corrections.
 Error messages
(1)
(2)
(3)