Doppler Centroid Estimation for Multireceiver SAS

For high-quality synthetic aperture SAS (SAS) processing, Doppler centroid estimation is an essential issue that can help us to solve the SAS platform's motion parameters conversely, construct azimuth matching function and is important for target location as well. In this paper, the Doppler centroid is estimated based on the energy balancing method, which uses two important functions, i. e., filter function and nominal azimuth signal power spectral density. Considering that the nominal azimuth signal power spectral density is often difficult to be obtained, it is approximately substituted by the average azimuth spectrum. The Doppler centroid can be obtained by inspecting the value of convolution result in the x-axis when y-axis is close to zero. At last, the presented method is validated by using the simulated data and real data.