Simulation of improved phase factor combined with step frequency in high resolution spotlight SAR

Along with the development of high resolution of radar techniques, in order to get a higher resolution, requirements of the range resolution and the azimuth resolution become much higher. That based on spotlight mode radar imaging mode has been used in high resolution SAR system widely. Large bandwidth signal synthetized step frequency aims to improve the range resolution, but at the same time causes various forms of error, which affects the quality of imaging seriously. Double sampling theorem can improve the azimuth resolution, which costs a large computation but has less efficiency. In this paper, the effects of error in narrowband synthesis scheme on the image quality evaluation index are analyzed. We put forward a method based on double sampling theorem combining synthetic bandwidth and improved phase factors transformation, which improve not only range resolution but also azimuth resolution cost a little computation, it values a lot in improving the quality of high resolution imaging.