An Improved Signal Processing Algorithm Based on Doppler Shifting Technique for Video-SAR

Abstract

One of the technologies in synthetic aperture radar (SAR) is Video-SAR (ViSAR). Previously, we proposed a new signal processing method to generate the multi-frames of ViSAR using Doppler shifting technique via sub-aperture. In this conference, we announce an improved Doppler shifting technique using Fractional Fourier Transform(FrFT). FrFT is one of the Signal Transform methods, which is to classify each signal from the overlapped frequency band. The previous technique only uses the matched filter in the slow-time plane to compress the interested signal. However, it cannot sufficiently guarantee the interested signal in a strong interfering environment. Therefore, to increase the quality of the signals for ViSAR frames, we apply FrFT into the Doppler shifting technique. By using FrFT technique, not only the quality of the interested signal has improved, but also a function to distinguish moving targets has been added. As a result, this proposed method is more efficient than the previous one, and at the same time, it also proposes a ViSAR algorithm with high performance by adding GMTI functions. We have performed the practical experiments using X-band chirp pulse SAR system mounted on an airplane to verify the proposed method.