A NEURAL TECHNOLOGY SMART SENSOR FOR SATELLITE ATTITUDE DETERMINATION

THE OBJECTIVE OF THIS INVESTIGATION IS TO DESIGNAND CHARACTERIZE A PROTOTYPE NEURAL TECHNOLOGY SENSORY SYSTEM, A "SMART SENSORY RETINA," TO PERFORM SATELLITE AND SPACECRAFT ATTITUDE DETERMINATION BY STAR PATTERN IDENTIFICATION. THE PROPOSED SENSOR CHIP IS CALLED A RETINA BECAUSE, LIKE BIOLOGICAL RETINAS, IT COMBINES OPTICAL TRANSDUCTION AND PREPROCESSING WITHIN A SINGLE ANALOG COMPUTING SURFACE. THE OUTPUT OF THE SMART RETINA IS A TRANSLATIONALLY AND ROTATIONALLY INVARIANT SIGNAL WHICH CAN BE USED FOR PATTERN IDENTIFICATION AND ATTITUDE CORRELATION. A FULLY INTEGRATED CHIP WHICH IMPLEMENTED THE RETINA AND IDENTIFICATION ALGORITHM IN SUBTHRESHOLD ANALOG VLSI COULD BEPLACED AT THE FOCAL PLANE OF A SIMPLE OPTICAL SYSTEM AND DIRECTLY OUTPUT STAR LABELS AND COARSE-ASPECT BORESIGHT ATTITUDE. THE DEVICE WOULD INITIALLY HAVE AN ULTRA-LOW CHIP COUNT DOMINATED BY INTERFACE CIRCUITRY, ULTRA-LOW MASS DOMINATED BY THE OPTICAL SYSTEM (A TWO ORDER OF MAGNITUDE SAVING) AND ULTRA-LOW POWER DISSIPATION ALSO DOMINATED BY INTERFACE CIRCUITRY (A SIX ORDER-OF-MAGNITUDE SAVING). LATER GENERATION FABRICATION AND PROTOPYING SUPPORTED BY FOLLOW-ON FUNDING WOULD INTEGRATE INTERFACE, SENSORY, AND PATTERN IDENTIFICATION CIRCUITRY TO RESULT IN A SINGLE-CHIP DEVICE. ANTICIPATED BENEFITS/POTENTIAL COMMERCIAL APPLICATIONS - THE PRELIMINARY ANALYSIS AND SIMULATION RESULTS PRESENTEDIN THE FOLLOWING PROPOSAL DOCUMENT SHOW THIS NOVEL DISTRIBUTED ANALOGCOMPUTATION APPROACH TO PROVIDE AN ENABLING LEAP IN AEROSPACE ELECTRONIC TECHNOLOGY. THE PROMISED SAVINGS IN MASS, POWER AND FUNCTIONALITYARE PRECISELY THE CHARACTERSTICS WHICH ARE REQUIRED IN AUTONOMOUS SATELLITE SENSORS IN GENERAL AND LOW-MASS HIGH-MANEUVERABILITY SDI WEAPONSYSTEMS IN PARTICULAR (E.G., BRILLIANT PEBBLES).