Improving the azimuth resolution based on ground based spotlight SAR

High resolution radars has many applications on ground monitoring application. Ground based SAR based on circle synthetic aperture is discussed in this paper. Since circle path SAR exists the contradiction between the resolution of azimuth and the capability of detection, Ground Spotlight SAR mode is proposed to solve the contradiction. On the basis of analysis of the geometry and of Spotlight SAR mode, the echo signal model is given and a simplified algorithm on range migration correction and modified range Doppler imaging algorithm are presented. The simulation results show the efficiency of the algorithm of range migration correction and imaging.