RD-Dechirp algorithm for curvilinear trajectory SAR quick look imaging

The problem of curvilinear trajectory synthetic aperture radar(SAR) quick look imaging for application in image matching guidance is addressed.The echo signal model of curvilinear trajectory SAR is built first,followed by an analysis of the characteristics of Doppler history and range migration.The concept of equivalent broadside imaging for curvilinear trajectory SAR is presented and its equivalent condition is also analyzed,which can significantly reduce the difficulty of range migration correction and the coupling between range and azimuth.Then two-dimensional spectrum of the echo is derived.On this basis,the quick look imaging algorithm combining range Doppler algorithm and spectral analysis(SPECAN) is proposed.The efficient SPECAN method for azimuth compression is used and the proposed algorithm is capable of processing the partial aperture data of curvilinear trajectory SAR coherently and accurately.Besides,the computational complexity is not increased though the aperture is non-linear.