Layout of a SAR sensor for Spacelab and satellite. Part 1: Design considerations for fundamental SAR parameters

Boundary conditions and design specifications for a Spacelab or satellite-borne C and X band radar are outlined. Ground resolution is 100 X 100 m for C band, 60 x 60 m for X band. Radiometric resolution is 1 dB for both. The Earth is initially assumed to be flat and stationary. Antenna length should be as large as possible so that the power budget is always favorable. Multilook processing is suggested, to increase radiometric resolution and image quality. The effects of azimuth and range ambiguities, beam width and complete coverage requirements on pulse repetition frequency are analyzed. Power budget for surface and point targets, with and without processing are discussed. The power budget for altitude line echo should enable a measure of the suppression required in the nadir direction to be estimated.