ALTITUDE MEASUREMENT IN HIGH-VELOCITY LOW-ALTITUDE VEHICLES

WE DESCRIBE TWO APPROACHES FOR MEASURING THE ALTITUDE OF A LOW-FLYING, HIGH-VELOCITY MISSILE ABOVE THE OCEAN SURFACE WITH A REMOTE RADAR. THE MEASUREMENTS ARE MADE BY FIRST RESOLVING THE DIRECT RETURN FROM THE MISSILE AND THE REFLECTIONS FROM THE OCEAN SURFACE. BECAUSE THE OCEAN SURFACE IS NOT A STATIONARY AND IDEAL MIRROR REFLECTOR, IT WILL NOT BE POSSIBLE TO USE CONVENTIONAL RADAR SIGNAL PROCESSING TO MAKE THESE MEASUREMENTS. HOWEVER, MARK RESOURCES HAS DEVELOPED NEW PROCESSING TECHNOLOGIES THAT ARE ESPECIALLY WELL SUITED FOR THIS PROBLEM. THE FIRST EXTENSION TO CONVENTIONAL RADAR SIGNAL PROCESSING IS TARGET MOTION RESOLUTION (TMR) PROCESSING, WHICH IS ESSENTIALLY SLIDING-WINDOW DOPPLER PROCESSING. IT ALLOWS ONE TO STABILIZE TARGET MOTION AND TO RESOLVE INDIVIDUAL SCATTERERS ON THE TARGET. IT IS VERY POWERFUL FOR TRACKING AND IMAGING SIMPLER TARGETS, SUCH AS MISSILES. THE DEVELOPMENT OF OUR SECOND EXTENSION TO RADAR SIGNAL PROCESSING BEGAN EIGHT YEARS AGO UNDER FUNDING BY AIR FORCE WRIGHT AERONAUTICAL LABORATORY (AFWAL) AND LATER DARPA. ALTHOUGH THIS ADAPTIVE SCATTERER MEASUREMENTS (ASM) TECHNOLOGY HAS BEEN DIRECTED TOWARDS TARGET IDENTIFICATION, IT IS COMPLETELY GENERAL, SO THAT IT APPLIES TO ALL RADAR PROBLEMS WHERE HIGH RESOLUTION IS INVOLVED, SUCH AS THE SUBJECT OF THIS SOLICITATION. WE HAVE ALREADY DEMONSTRATED VERY HIGH MEASUREMENT PERFORMANCE WITH BOTH TMR AND ASM IN SIMILAR APPLICATIONS. DURING PHASE I WE PLAN TO DEMONSTRATE THE POTENTIAL PERFORMANCE FOR MEASURING TARGET ALTITUDE BY PROCESSING ACTUAL RADAR DATA.