An improved method for the estimation of the Doppler centroid frequency
Cheng Yuping Bao Zheng (National Key Lab. of Radar Signal Processing, Xidian Univ., Xian, 710071)
In synthetic aperture radar (SAR) imaging and its application, it is necessary to estimate the Doppler centroid frequency accurately. The azimuth power spectra may be distorted due to the presence of the bright target that has been illuminated by a partial aperture, thus affecting the estimation of the Doppler centroid frequency. In this paper, we propose a time frequency filtering method based on the analysis of the model of the time frequency distribution of the Doppler phase history. This method can improve the azimuth power spectra and the precision of the Doppler centroid frequency estimation by filtering the time frequency distribution of the target illuminated by a partial aperture. The effectiveness of this method has been demonstrated by experimental results.