Design of return signal simulator for SAR ground-based test and calibration

Abstract

Ground-based test and calibration of Synthetic Aperture Radar (SAR) is a very complex program. It needs a practical method and technique to provide a full return signal simulation over the range of in-orbit operating conditions before launch for such a program. Compared with conventional ground-based test methods, the Return Signal Simulator (RSS) is more effective for full system validation and makes test program and procedure greatly simplified. Based upon signal processing of SAR, an advanced RSS system is designed. By using chirp regeneration method, the RSS can achieve 1-10ms time delay between SAR transmitting and simulated signal return, which will realize round trip path delay simulation for various orbit height; By using digital synthesizing method, various target return signal can be simulated. So the RSS system can make prelaunch performance of SAR well known, and this will be very helpful for radiometric calibration after launch. This paper will give detailed description on the RSS system design with its means of testing and calibrating of satellite SAR.