Research On Image Formation Algorithm For Missile-borne Stripmap SAR Based On Improved PFA

Synthetic aperture radar imaging technology is a breakthrough achievement in the field of modern science and technology,its appearance has greatly expanded the concept of traditional radar.In today's society,it is playing a more and more important role in the modernization of national defense technology and the development of the national economy.PFA is a classic spotlight SAR imaging algorithm,there are so many advantages that the algorithm has been widely used.But in the process of theoretical derivation,PFA is based on the assumption of strictly planar wavefront,so that the effective focusing radius of PFA algorithm is limited seriously,which limits its further application severely.Some improved methods have been proposed and these methods have extended PFA's focusing range greatly,however,these methods can be only used in the radar height constant situation,in some special applications,such as missile borne SAR,radar inevitably exists diving,these improved methods have been unable to be directly applied.By improving the PFA algorithm,now,this algorithm has been able to be applied to the radar dive mode successfully,in addition,in this master's thesis,the improved spotlight SAR imaging algorithm is also applied to the missile borne stripmap SAR imaging.The main work of thesis are as follows:(1)the polar format algorithm(PFA)and the wavefront error compensation of PFA in the radar height constant situation are introduced in detail.(2)We studies the wavefront curvature error compensation problems of radar dive situation and the wavefront curvature correction method for dive situation is proposed,the compensation precision is also analyzed.(3)We studies the principle of subaperture stripmap mosaic imaging algorithm,a subaperture stripmap mosaic imaging algorithm based on PFA under missile borne dive squinted condition is proposed,the effectiveness and feasibility are verified by simulations.