A new method to estimate Doppler parameters for synthetic aperture radar in target echo signals

Necessary element of the signal processing for synthetic aperture radar (SAR) systems. Without proper resolution of the Doppler centroid (DC) and the Doppler frequency rate (DFR), the imaging quality will be degraded in the system impulse function, geometric fidelity and focus. A technique for the resolution of the DC and the DFR estimation ambiguity for the spaceborne SAR is presented in this paper without knowing any initial values of the DC and the DFR in target echo signals. According to the spectral power figure that the DC is determined by the center coordinators of two peaks and the DFR is determined by the width between the two peaks. The achievable accuracy is derived theoretically and verified by tests using ERS-2 simulated echo data