THIS PROPOSAL OUTLINES A TOPOGRAPHIC OR TERRAIN ELEVATION DATA STORAGE AND RETRIEVAL SYSTEM WHICH ACHIEVES SUPERIOR PERFORMANCE BY THE USE OF DATA COMPRESSION.

THIS PROPOSAL OUTLINES A TOPOGRAPHIC OR TERRAIN ELEVATION DATA STORAGE AND RETRIEVAL SYSTEM WHICH ACHIEVES SUPERIOR PERFORMANCE BY THE USE OF DATA COMPRESSION. A PROMISING COMPRESSION TECHNIQUE IS OUTLINED. WHILE THE DESIGN OF THE "ON LINE" DECOMPRESSION HARDWARE IS FAIRLY STRAIGHTFORWARD, THE OFF LINE COMPRESSION OF THE SOURCE DATA, WHICH IS BLOCKED AND RECTIFIED DEFENSE MAPPING AGENCY LEVEL 1 ELEVATION DATA, INVOLVES SOME NON TRIVIAL PROBLEMS. TWO OF THESE PROBLEMS, NAMELY EFFICIENT MEANS OF EXTRACTING LARGE "KEYS" (IN THE CRYPTOGRAPHIC SENSE) FROM THE DATA BASE, AND SECOND, USING THESE KEYS TO EFFICIENTLY ENCODE THE SOURCE DATA WILL BE INVESTIGATED USING COMPUTER SIMULATION. THE RESULTS EXPECTED SHOULD MAKE POSSIBLE AN ELEVATION DATA STORAGE AND RETRIEVAL SYSTEM WITH A CAPACITY IN THE VICINITY OF 1 MILLION SQUARE MILES, AN ACCURACY COMMENSURATED WITH THAT OF THE SOURCE DATA, AN ACCESS TIME FAST ENOUGH FOR USE ON BOARD AIRCRAFT, AND A SIZE, WEIGHT, AND POWER CONSUMPTION SUITABLE FOR USE ABOARD EVEN FIGHTER AIRCRAFT.