Research On Missile-borne Synthetic Aperture Radar Imaging

Synthetic Aperture Radar (SAR) is a kind of active microware remote sensingimaging radar, which has high resolution. Missile-borne SAR is an important branch ofSAR, which can improve the strike precision and power via sense matching of SARreal-time image and SAR image stored in the system. However, because of the highvelocity and flexibility, missile-borne SAR is different from the conventional air-borneand space-borne SAR. According to the instinctive features of missile-borne SAR, thesystem parameters design of missile-borne SAR system, motion compensation andhigh-squint SAR imaging algorithm are discussed in this dissertation respectively.1. Focusing on the range and azimuth resolution, the imaging theory of syntheticaperture radar is analyzed. Also, the Range-Doppler (RD) algorithm and Chirp Scaling(CS) algorithm are introduced respectively. Then, the SAR system parameters design iscompleted via the analysis of the missile’s motion features.2. First, the motion-errors of missile platform are discussed. Then, a novel contrastoptimization autofocus algorithm is presented for the shortages of original algorithms.The results obtained prove that this autofocus algorithm has the advantages of fastconvergence speed and strong robust ability. Finally, a real-time SAR algorithm basedon motion compensation is presented, and the experiment results demonstrate thevalidity of this algorithm.3. First, the geometric model of high squint SAR imaging is built. Second, a detailstudy is preformed on the Taylor extension of the range model and the decouplingerrors of the signal expression in2D frequency domain. Then, based on range walkcorrection in time domain and range curvature correction in frequency domain, a highsquint Range-Doppler algorithm is presented, in which cubic range cell migrationcorrection is considered. Finally, the simulation results demonstrate the validity of thisalgorithm.