ELEVATIONS FROM RADAR IMAGERY

RADAR IS A RANGING DEVICE WHITE THE CAMERA IS AN ANGLE- MEASURING DEVICE. THIS DIFFERENCE MEANS THAT ENTIRELY DIFFERENT RELATIONSHIPS ARE USED FOR ELEVATION MEASUREMENTS. AS RADAR PROVIDES ITS OWN SOURCE OF ILLUMINATION,IT ALSO HAS CAPABILITIES NOT AVAILABLE WITH CONVENTIONAL CAMERAS. FOR EXAMPLE, UNDER CERTAIN CIRCUMSTANCES, THE HEIGHT OF VERTICAL FEATURES CAN BE DETERMINED SOLELY FROM THE IMAGE ITSELF WITH NO KNOWLEDGE OF THE RADAR SYSTEM OR AIRCRAFT POSITION. RADAR CAN ADDITIONALLY HAVE EITHER SLANT OR GROUND RANGE IMAGES. EACH TYPE OF IMAGE REQUIRES THE USE OF DIFFERENT GEOMETRICAL RELATIONSHIPS. THIS PAPER DEVELOPS THE MATHEMATICAL EXPRESSIONS FOR MEASURING THE HEIGHTS OF VERTICAL AND NON- VERTICAL FEATURES WITH BOTH SLANT- AND GROUND-RANGE IMAGES. SIGNIFICANT APPLICATIONS ARE DISCUSSED AND THE EXPERIMENTAL ACCURACIES OBTAINED IN ACTUAL PRACTICE ARE GIVEN. /PE/