Abstract:

A new method based on fractional Fourier transform (FrFT) is put forward to solve the problem of real-time parameter estimation of space-borne synthetic aperture radar (SAR) signals. The concept of FrFT and its estimation theory of chirp signals are introduced firstly. Then, after analyzing the feature of SAR flight, real-time parameters estimation are carried out respectively to cases of single pulse and pulse trains. FrFT is firstly applied to single pulse in the received signals, which can estimate the carrier frequency and rate of SAR signal. Then, FrFT is applied to pulse trains, which can estimate the azimuth rate of SAR signals. Theoretical analysis and numerical simulations show high accuracy of this method.