Optimal Doppler Centroid Estimation for SAR Data from a Quasi-Homogeneous Source

In synthetic aperture radar (SAR) signal processing, an accurate Doppler centroid is required for most applications involving target motion estimation and antenna pointing direction estimation. In some cases the Doppler centroid can be sufficiently determined using available information regarding the terrain topography, the relative motion between the sensor and the terrain, and the antenna pointing direction. But most often, a highly accurate Doppler centroid value has to be derived by analyzing the received SAR signal itself. This kind of signal processing is referred to as Doppler centroid estimation (DCE). This correspondence briefly describes two DCE algorithms, provides a performance summary for these algorithms, and presents the experimental results. These algorithms include a previously reported one and a newly developed one that is optimized for quasi-homogeneous sources. The performance enhancement achieved by the optimal DCE algorithm is clearly demonstrated by the experimental results.