A novel SAR imaging method under geographical coordinates
后向投影算法的地理坐标系下的合成孔径雷达成像

Traditional airborne SAR (Synthetic Aperture Radar) makes use of the GPS/INS to compensate the platform motion error to acquire high resolution images. GPS data with geographical coordinates (consists of longitude, latitude and height) is converted to a local Cartesian coordinates, under which raw radar data is processed with some imaging and motion compensation algorithms to create an image with the local coordinates. However, it is not easy to be understood for other departments who need an image located by geographical coordinates. This paper presents a novel SAR imaging algorithm derived from Back-Projection that can be processed directly under the geographical coordinates and avoid coordinates transformation. Each pixel of the image obtained via this algorithm is located with geographical coordinates, which is convenient to be applied by the intelligence or other survey departments. Images obtained under geographical coordinates by this algorithm are as clear as traditional algorithms that been proved by simulations and an outside experiment.