Azimuth spectrum reconstruction using FrFT for formation-flying satellites SAR

Spatial azimuth samples provided by formation-flying satellites are almost irregularly spaced and can be represented as a periodic non-uniformly sampling because of the influence of various factors; consequently, traditional imaging algorithm produces unsatisfactory results. In order to solve this problem, the theory of Fractional Fourier Transform (FrFT) is introduced and azimuth spectrum reconstruction algorithm based on FrFT for formation-flying satellites SAR is proposed. Not only the proposed reconstruction algorithm can reconstruct uniform signal spectrum along the track from periodic non-uniformly sampled signal, it can also be utilized to carry out high-resolution and wide-swath simultaneously for formation-flying satellites SAR system. Finally, simulations are presented to verify the theory.