Accession Number : ADA306159

Title :   Design Study for Passive Sensor Altitude and Terrain Awareness System.

Descriptive Note : F41624-92-C-6007

Corporate Author : CHARLES RIVER ANALYTICS INC CAMBRIDGE MA

Personal Author(s) : Miao, Adam X. ; Zacharias, Greg L.

PDF Url : ADA306159

Report Date : JUN 1995

Pagination or Media Count : 120

Abstract : This Phase II effort completed the successful enhancement, implementation, and demonstration of the passive sensor Altitude and Terrain Awareness System (ATAS) operation using both computer generated and real imagery. The products of this effort include: (1) a test bed and an overall architecture of ATAS that comprises both the real-time image generation and real-time egomotion and terrain shape estimation; and (2) hardware and software specifications for a real-time flight rated ATAS. The test bed is composed of a flat-terrain image generator that produces CGI frames simulating perspective images viewed by an observer (camera) flying over flat terrain decorated by arbitary sinusoidal patterns, a rolling-terrain image generator that produces video (analog) imagery simulating images viewed by an observer flying over a sinusoidal rolling terrain decorated by sinusoidal patterns, and a frame grabber using hardware and software image grabbing tools hosted by a Macintosh Quadra 840 AV computer. ATAS is composed of an image processor; a snapshot egomotion and terrain shape estimator; and a Kalman filter, to provide smoother high-accuracy on-line estimates. Furthermore, we developed two types of egomotion and terrain shape estimators to deal with different kinds of terrain conditions: a geometry-based estimator and a structure-based estimator. We conducted a successful on-line demonstration of the ATAS ground-based prototype, driving the system with CGI and flight-recorded imagery, generating running estimates of altitude and attitude with respect to the overflown terrain. (MM)

Descriptors :   *AIR NAVIGATION, *TERRAIN AVOIDANCE, *TERRAIN FOLLOWING, IMAGE PROCESSING, ROLL, ROBOTICS, ATTITUDE CONTROL SYSTEMS, PITCH(INCLINATION), YAW, FORWARD LOOKING INFRARED SYSTEMS, KALMAN FILTERING, INERTIAL NAVIGATION, ALTITUDE, PIXELS, COLLISION AVOIDANCE, VIRTUAL REALITY.

Subject Categories : Cybernetics
      Air Navigation and Guidance

Distribution Statement : APPROVED FOR PUBLIC RELEASE