On the optimisation of distributed ambiguity ratio and directivity for a synthetic aperture radar

Space borne Synthetic Aperture Radar (SAR) is a radar capable of high resolution imaging of the surface of the earth. Typical applications of a space borne SAR include the observation of oil slicks, ice packs, shipping lanes, industrial pollution and agricultural usage. The SAR spacecraft travels in a low earth orbit focusing a narrow radiation pattern upon the earth in the direction along the plane of travel and a wide beam in a plane transverse to this. Whereas the narrow along track or azimuth beam is fixed normal to the spacecraft, the wide elevation beam must have the ability to scan over the surface of the earth. The objective of this paper is to describe a new method of determining the array excitations that form this wide elevation beam taking account of both the antenna and the radar system characteristics.