combination of rda with pga method to appropriate image formation on sar with ballistic motion

one of the main concerns of processing algorithms used in synthetic aperture radar (sar) with a ballistic motion is the compensation of all phase errors in the data received from the target to achieve a clear picture of the target. in this article, by using range doppler algorithm and phase-gradient auto focus algorithm, imagery in one sar with a ballistic motion is considered according to the geometry of sar with a ballistic motion. this process is a combination of range-doppler processing algorithm and phase-gradient auto focus algorithm. the significant characteristic of this method is that it does not need to collect information from navigation systems for motion compensation and any kind of phase error decreasing. furthermore , this algorithm can estimate speed and acceleration of sar motion, and, thus, the phase error existing in received data will be tending to zero. the innovation made in this article is to improve phase-gradient auto focus algorithm in choosing the prominent scatterrer stage by the correlation operator. recent characteristic provides the possibility of imagery from a wide scene from the target.