Synthetic aperture radar imaging using nonlinear frequency modulation signal

In this paper, a new nonlinear frequency modulation (NLFM) waveform is developed that can be used as a transmitted chirp in synthetic aperture radar (SAR) imaging to improve the imaging quality compared to a linear frequency modulation (LFM) chirp signal. The new NLFM is constructed based on piecewise linear functions, which are optimized using multi-objective optimization. Different signal processing algorithms are investigated in order to use NLFM as the transmitted chirp in a SAR system. In addition, a modified motion compensation (MC) algorithm using navigation data is proposed for the range-Doppler algorithm. Strip-map SAR geometry is considered to generate a SAR raw signal, in order to validate the new offered chirp signal and the proposed MC algorithm.