SIR-B image calibration by a corner reflector array

Abstract

SIR-B image data taken over a corner reflector array are analysed to calibrate the image and to estimate the 3dB resolution. Square trihedral corner reflectors having different radar cross-sections (RCSs) are successfully used to relate an image data number to RCS. RCS of the background surface is estimated and its effect is also included in the above relation. The 3dB resolutions are estimated by two independent techniques. The results obtained from the two techniques agree with each other within their relative difference by 5·6 per cent except for one case. The estimated resolutions are larger than those predicted by the Jet Propulsion Laboratory. The estimates should be regarded as the image resolutions and do not represent the sensor characteristics.