MIT
ICAT
y
Altimetry
Standard Atmosphere Referenced
† 29.92 inches of Hg
† 3014 mb
y
Pressure Altitude
† Altitude of Pressure in Std Atmosphere
† Used above reference Flight Level (FL180 in US)
y
Density Altitude
† Altitude of density in Std Atmosphere
† Used for performance (TO)
y
Barometric Altitude
† Estimated altitude corrected for surface pressure
† MSL Altitude above Mean Sea Level (QNH)
† AGL Altitude above Ground Level (QFE)
y
Radar Altitude (Cat II and III Approaches)
† 5 cm radar - normally only below 3000ft (Terrain Noise)
y
Cabin Altitude (Pressurization)
MIT
ICAT
Airspeed
y Pneumatic Measurement based on Dynamic Pressure
† Pitot and Static
y Indicated Airspeed
† Indicated on Instrument
† Measurement of pressure on Aircraft (ie Load)
† Used for structural operating limits
y Calibrated Airspeed
† Pitot-Static Errors Calibrated out
† Used for Flight Test and Performance
y Groundspeed
† Achieved speed over ground
y Mach Number
† Requires Static Air Temperature
MIT
ICAT
Air Data Sensors
y Pitot Tube
† Heated for De-Ice
y Static Port
†
†
†
†
Location Sensitive
Typically 1/3 Back on Fuselage on Conventional aircraft
Bilateral with crosstie to avoid Side Slip Errors
Water Drain
y Alpha Vane
† Heated for De-Ice
y TAT Probe
† Inertial Separator for Water
† Heated for De-Ice
MIT
ICAT
y Static Air Temperature
y Ram Rise
y Total Air Temperature
Temperature
MIT
ICAT
Integrated Air Data Systems
y Air Data Computer
† Compensates out Static System Errors
† Citation Example
y Air Data Heading and Reference Systems (ADHARS)
MIT
ICAT
y
Heading
Magnetic Compass
† Variation (Magnetic Deviation
† Deviation (Magnetic materials)
‹ DC9 Example
† Compass Card (Calibrated with Radios and Equip on)
y
Flux Gate Compass
† Electronic Magnetic Compass
‹ Normally in Tail for deviation
y
Gyro Compass
† Precession
† Slaved Flux Gate
y
Turn Coordinator
† (Rate Gyro)
MIT
ICAT
y
Inertial Reference Unit
Integrate acceleration from known position and velocity
† Velocity
† Position
y
Need Heading
† Gyros
‹ Mechanical
‹ Laser
y
Can get Attitude
† Artificial Horizon (PFD. HUD)
y
Drift Errors
† IRU unusable in vertical direction (need baro alt)
† Inflight Correction
‹ DME
‹ GPS
‹ Star Sighting for Space Vehicles
y
Measurement Give Attitude Also
y
777 Analytical Redundancy
MIT
ICAT
Communications
y Requirements
† Communicate necessary information between formation elements and
command node (LAN and Air-Ground)
† Bandwidth
† Low-Observable?
† Synchronous vs asynchronous
y Constraints
† Spectrum
† Antenna Location
y Technologies
† Radio
‹ UHF, VHF, MMW
† Optical
‹ Laser
† Protocols
MIT
ICAT
y
COMMUNICATION
Voice
† VHF (line of sight)
‹ 118.0-135.0 Mhz
‹ .025 spacing in US, 0.083 spacing in Europe)
† UHF
‹ 230-400 Mhz (guess)
† HF (over the horizon)
† Optical (secure)
y
Datalink
† ACARS (VHF) - VDL Mode 2
† VDL Modes 3 and 4 (split voice and data)
† HF Datalink (China and Selcal)
y
Geosynchronous (Inmarsatt)
‹
Antenna Requirements
y
LEO and MEO Networks
y
Software Radios
y
Antenna Requirements
MIT
ICAT
Bandwidth Growth Trend
Source: DOD UAV
Roadmap, 2000
MIT
ICAT
Navigation
(relates to Surveillance)
y Requirements
†
†
†
†
General Navigation (medium precision)
Station Keeping (high precision)
Integrity
Availability
y Constraints
† Existing nav systems
† Loss of signal
y Technologies
† GPS/Galileo (need Differential)
‹ Code vs Carrier Phase Approaches
† IRS/GPS
† Sensor Based Approaches for Station Keeping
‹ Image (Visible, IR)
‹ Range Finders (Laser, Ultrasonic)
MIT
ICAT
NAVIGATION (ENROUTE)
y Radionavigation beacon
†
†
†
†
VHF Omnidirectional Range (VOR)
Non-Directional Beacon (NDB)
Distance Measuring Equipment (DME)
TACAN
y Area navigation systems (ground based)
† Omega
† LORAN
y Inertial navigation systems
y Satellite navigation systems
† GPS (CA)
† GNSS (Galileo?)
MIT
ICAT
GPS
(Courtesy of Peter Dana. Used with permission.)
From http://www.Colorado.Edu/geography/gcraft/notes/gps/gps_f.html
MIT
ICAT
GPS
Courtesy of Peter H. Dana, The Geographer's Craft Project, Department of Geography, The University of Colorado at Boulder. Used with permission.
From http://www.colorado.Edu/geography/gcraft/notes/gps/gps_f.html
MIT
ICAT
y
GPS ISSUES
Requirements
† Accuracy
† Integrity
† Availability
y
Selective Availability (SA)
† Degraded to 100m accuracy
y
Control by US DoD
† International concerns
y
US guarantee of service free to world
through 2005
y
Vulnerability to jamming
y
DGPS
† WAAS
† EGNOS
† LAAS
MIT
ICAT
NAVIGATION TRENDS
(APPROACH)
y Instrument Landing System (ILS)
† Cat. I (200 ft; 1/4 mile)
† Cat. II (50 ft; 800 RVR)
† Cat. III (0,0)
y Microwave Landing System (MLS)
y GPS (100m)
† Wide Areas Augmentation System (5m)
‹ LNAV-VNAV (250, 1/4 mile)
† Local Area Augmentation System (0.1m)
‹ Cat. III?
y Change to Required Navigation Performance (RNP)
† RNP X
† X is 95% lateral containment on NM
MIT
ICAT
NAVIGATION TRENDS
(APPROACH)
MIT
ICAT
NAVIGATION TRENDS
(APPROACH)
MIT
ICAT
GPS Approach Navigation
y Requirements
† Accuracy (RNP)
† Availability
† Integrity
y Differential GPS
† Wide Area Augmentation System (WAAS)
† Local Area Augmentation System (LAAS)
MIT
ICAT
Surveillance
y Requirements
† Observed states of lead elements sufficient to form-up and maintain
† Feed forward states (intent)
y Constraints
† Sight Angles
† Installation (weight, cost, power, etc)
† Cooperative Targets
y Technologies
†
†
†
†
†
Automatic Dependant Surveillance Broadcast (ADS-B)
Image Based Systems (Vis, IR)
Radar (X Band, MMW0
Range Finders (Laser)
Sensor Fusion Systems
MIT
ICAT
y Weather Radar (10 CM)
y Search and Track
† Doppler
y Synthetic Aperture Radar
y Radar Altimeter
RADAR
MIT
ICAT
RADAR
y Wavelength λ
†
†
†
†
S Band (10 cm)
X Band (3 cm)
Ku Band (1 (cm)
Millimeter Wave (94 Ghz pass band)
y Radar Range Equation
y Beamwidth Θ
† Θ = λ/D
† D = Diameter of Circular Antenna
† Pencil beam vs Fan Beam
y Mechanically Steered Antennas
† Scan and Tilt
MIT
ICAT
Imaging and Night Vision Systems
y Infrared
† Special Optics (eg Gallium Arsinide)
† Water Contamination
† Sensor Cooling Requirements
y Image Intensifier Systems
y Pointing Systems
MIT
ICAT
Datalink Based Systems
y JTIDS
y Mode S Transponders
† Traffic Information Service
y ADS-B
MIT
ICAT
Self Reporting Aircraft States
ADS-B
(Image removed due to copyright considerations.)
Bob Hilb
UPS/Cargo Airline Association
MIT
ICAT
INTENT REPRESENTATION
(consider other states)
y Intent formalized in “Surveillance State Vector”
Surveillance State
Vector, X(t)
Position states, P(t)
⎫
⎧
⎪ Traditional dynamic
⎪
Velocity
states,
V(t)
⎪
⎪
states
⎪⎪ Acceleration states, A(t) ⎪⎪
= ⎨
⎬
Current
target
states,
C(t)
⎪
⎪
Defined intent
⎪ Planned trajectory states, T(t)⎪
states
⎪
⎪
⎪⎩ Destinatio n states, D(t) ⎪⎭
y Accurately mimics intent communication & execution in ATC
Current
target state, C(t)
MCP
PILOT
FMS
Planned
trajectory, T(t)
Destination, D(t)
MIT
ICAT
ADS-B SURVEILLANCE
ENVIRONMENT
y Potential access to more states (e.g. dynamic and intent)
y Need to assess benefits for conformance monitoring
ACTUAL SYSTEM REPRESENTATION
PILOT
INTENT
A/C
CONTROL
AIRCRAFT
INTENT
SYSTEM
DYNAMICS
Trajectory, Target
A/c
Control
Nav.
Position, P(t)
Destination states, accuracy surface property Velocity, V(t)
Guidance e.g. ANP inputs e.g. weight Accel., A(t)
mode
ADS-B SURVEILLANCE SYSTEM
Trajectory Target
states
Other useful
states???
Position,
Baro altitude
Heading, Speeds
Roll, ...
MIT
ICAT
Engine Instrumentation
y Rotation Rates
† N1
y Exhaust Pressure Ratio
y Temperatures
† Turbine Inlet Temperature
y Oil Pressure
y Oil Temp
y Vibration
MIT
ICAT
Warning Systems
y Master Caution
† Fire
† Low Pressure (eg oil)
†…
y Stall Warning
† Stick Shaker
y Traffic Collision Avoidance System (TCAS)
y Enhanced Ground Proximity Warning System (EGPWS)
y Envelope Protection
MIT
ICAT
Envelope Protection
Fly-by-wire protection - Normal Law
Ground
mode
Pitch
attitude
Load
factor
Bank
angle
Takeoff
mode
Flight
Flight
mode
mode
Flare
mode
High
*AOA
* Angle of Attack (AOA)
Overspeed
Ground
mode
High Angle of Attack
Protection
MIT
ICAT
Airspeed scale
CL
CL
140
VLS
Vα Prot
Vα Floor
α Angle of Attack (AOA)
120
Vα Max
α Stall: Sudden loss of lift and or aircraft control
α Max:
Angle of attack reached with full aft stick
(max aircraft performance)
α Floor: Angle of attack, where TOGA thrust is
automatically applied by the A/THR
α Prot: Angle of attack from which stick input is converted
into angle of attack demand (stick neutral α Prot)
α VLS: Angle of attack reached at approach speed (VLS)