Study Of Airborne SAR Imaging Algorithm And Real-time Imaging System

Synthetic aperture radar (SAR) is a kind of imaging radar placed in moving platform such as airplane and satellite , was born in the 20th century, 50's, is a new type of radar system. Because SAR has the advantage that it is free of weather influence, and works in both day and night, it can greatly improve radar's capability of collecting information. It employs the principle of synthetic aperture and pulse compression technology. Hence it makes the azimuth resolution limitations of the real single antenna aperture untenable, and is able to get the two-dimensional high-resolution imaging of long-range. So, SAR has a tremendous practical value in the military and civilian areas. In this thesis, the author discusses how to get the high quality and precise SAR image from the wide scene high-resolution SAR real measured data using the motion compensation algorithm. And by utilizing the advantage of the accuracy and efficiency of the high-resolution real-time SAR imaging system, the Doppler parameter estimation is implemented using the"ping-pong"operation in the signal processing, which meets the demands for real-time imaging of the motion compensation and azimuth focusing accuracy. Then the results of the simulation shows that the performance of the methods and algorithms mentioned above are satisfied.Specific arrangements are as follows:The first chapter reviews the development history of SAR, and introduces the airborne SAR briefly.The second chapter firstly describes the theory of SAR imaging, according to analyzing influence of range cell migration for SAR imaging, and then discusses the common imaging algorithms, such as RDA and CSA.The third chapter is concerned with motion compensation based on radar echoes in unstable flat during SAR imaging and analyses connection of SAR image.The fourth chapter proposes a method of Doppler parameters estimation quickly based on a kind of signal processing platform which is composed of DSP named TS -201 and FPGA.And in the last chapter, there are summary and prospect of this dissertation.