The Research On Side-Look Array Processing Imaging Of The Distributed Spaceborne SAR System

Synthetic Aperture Radar (SAR) is the product of modern high science and technology, it has been widely used in the areas of military and civil and it has brought great benefits in economics and society. With the need of applications, people desire to not only get the high resolution two-dimensional image of the ground quiescent targets and moving targets, but also get the three-dimensional image. The high resolution is obtained by turning time into spatial position in individual spacebome SAR, as a result the imaging quality and scope of application is definite to be restricted. The Distributed Spacebome SAR System is constituted by the cluster of SAR satellite, it has the advantage that information of time and space is collected and it will has more than ever functions and fine imaging quality by making use of the information of time and space.This dissertation bases on the subject "The Research on Side-Look Array Processing Imaging of the Distributed Spacebome SAR System", mostly to research the two-dimensional SAR imaging by the side-look array processing of the Distributed Spacebome SAR System. This subject is belonging to the subject "The General Technology Argumentation of the Distributed Spacebome SAR System". The research on the Distributed Spacebome SAR System is just now is under way in national and international, therefore this research works take on vital significance.The Distributed Spacebome SAR System is making up of multiple spacebome SAR. If the individual spacebome SAR is treating as a sensor, the Distributed Spacebome SAR System constitutes the side-look array of SAR sensors. The information of space-time or space-frequency can be used to produce SAR imagery with fine quality and accomplish the moving target imaging by the side-look array processing of echoes data. This dissertation deeply research on the side-look array processing imaging of Distributed Spacebome SAR System, and the main content of this paper can be concluded as following:1. The range migration of the spacebome SAR signal is inevitable phenomena, the different SAR imaging algorithm takes on the different correction wayabout the range migration. Based on the range migration of range-Doppler (RD) domain, this dissertation detailed analyzes the difference of the range migration by the earth rotation and the beam squint in RD domain, and the effect of range migration correction in time-domain and frequency-domain to imagery quality, and introduces general imaging algorithm of spacebome SAR.2. The spatial correlation between two SAR imagery is related to they are whether the imagery of the same terrain, and that the look correlation is relative with the suppressing of the speckle. Based on the Distributed Spaceborne SAR System, this dissertation thoroughly analyzes the spatial correlation and the looks correlation between SAR imagery, and the Doppler parameter characteristic of echoes signal of Distributed Spaceborne SAR System. Individual SAR imaging algorithm is proposed aim at the Doppler parameters characteristics of Distributed Spacebome SAR System.3. The Distributed Spacebome SAR System in side-look mode, it constitutes the side-look sensor array, the echoes signal of each spacebome SAR possesses the information of space-time. Based on the complex image of the side-look array, this dissertation proposes the imaging algorithm of the non-coherent processing, the beamforming processing and the beamforming and the non-coherent processing by making use of the information of space-time of the side-look array, and take theoretically analysis for SAR image quality improvement.4. The SAR resolution of range and azimuth is determined by the signal bandwith, and the bandwith of echo spectrum is determined by the signal bandwith, thus the resolution is determined by the bandwith of the echo spectrum. The dissertation detailed analyzes the relation between the echo spectrum of range, azimuth and the resolution of range, azimuth, and proposes improving resolution algorithm by shifting in frequency and in...