Design of a monopulse SAR system for the determination of elevation angles

Terrain height variations in mountainous areas cause problems in the radiometric correction of SAR images. The authors propose a novel SAR system which exploits the monopulse principle to determine the elevation angle and thus the height at the different parts of the image. From the ratios of images radiometrically modulated by the difference and sum antenna pattern in cross-track direction, the authors can calculate the appropriate elevation angle at any point in the image. In this paper, they present design considerations for an array antenna for DLR´s airborne X-band SAR system and give estimates of the error due to system noise and azimuth ambiguities as well as the expected performance and precision in topographic mapping