High-Resolution SAR Imaging

As an active microwave remote-imaging system, synthetic aperture radar (SAR) has applied in the field of military reconnaissance, the field of resource exploration and the filed of disaster watch. SAR has the all-weather, day/night capability to generate a high-resolution representation of the targets over a long range, so it can enhances radar's information acquisition capability and information awareness ability.This dissertation investigates the problem of synthetic aperture radar imaging algorithms, Doppler rate estimating, Motion Compensation and phase error analyzing. The main contents of the dissertation are described as following.1,SAR imaging algorithm. The differences between high-band SAR and low-band SAR are analyzed. The CS imaging algorithm and NCS imaging algorithm are studied, and we analyze the phase error caused by the approximate of the imaging algorithms. Based on the study of effective swath and effective range in multi-SAR, the imaging algorithm of high-band SAR and low-band SAR are studied.2,Doppler rate estimating and Motion Compensation. The Doppler rates of high-band and low-band SAR are studied. MD and COAA algorithms are analyzed. The criteria of selecting range bin, spectrum resolution and the length of sub-aperture data are studied. The algorithms of motion compensation are proposed in the condition of large and small swath.3,The study of Motion Compensation. Based on the using of imaging and motion compensation in multi-SAR, the phase of SAR is analyzed. The phase errors of SAR are exacted after and before motion compensation. On the basis of phase error, the spectrum of the phase error and the focusing performance of motion compensation are studied.