Doppler Parameters Calculation of SAR Based on Satellite Ephemeris

An improved method of calculating space-borne synthetic aperture radar( SAR ) Doppler parameters is presented. The method relates to the satellite ephemeris. The improved method introduces J2 perturbation influence on perigee amplitude and longitude ascending node to Doppler parameters calculation effectively and obtains more accurate Doppler parameters. The difference between the traditional method and the improved method is analyzed, and the accuracy of the improved method is verified through computer simulation.