A Novel Data Preprocessing Method for Resolving Doppler Ambiguity of Spaceborne Spotlight SAR

This paper presents a novel data preprocessing method for resolving Doppler ambiguity of spaceborne spotlight synthetic aperture radar. The new method enhances the azimuth sampling rate of received data by taking dechirping operation and increasing chirp rate operation combined with Fast Fourier Transform (FFT) and Inverse FFT (IFFT). On premise of maintaining imaging quality, Pulse Repetition Frequency can be decreased to the lowest value by this method, which avoids the subapertures recombination difficulty of traditional Subaperture Processing Technique. Finally, simulation results demonstrate the validity of this method.