Estimation of Doppler Parameter for Formation-Flying Satellite SAR System

Abstract

In formation-flying satellite SAR system, especially the satellites are LEO or MEO, Doppler frequency shift of SAR echo has a character of long-range changes and quick time variation. Because of this, imaging with high quality become difficulty. Based on the theories and methods of universal gravitation, the relative positions and velocities between every satellite and the ground detection center can be computed, then the Doppler frequency shift for formation-flying satellite SAR system can be estimated that only need to known the parameters of satellite orbit, the working frequency and the azimuth of antenna of master satellite radar. The simulation results show that by using this method, the scope of Doppler frequency shift can be reduced to a very small range, about two in a thousand compared to original echo.