Polar Format imaging algorithm based on range scaling for spotlight SAR

There are two main problems through the implementation of Polar Format Algorithm (PFA). First, the error of Residual Video Phase (RVP) arises after the dechirp operation. Second, the interpolation has influence on the computation efficiency and imaging precision. This paper proposes a novel algorithm where range resampling is based on the principle of Scaling and Chirp-Z transform is adopted on azimuth dimension. The presented approach only consists in FFTs and multiplications, which effectively helps to decrease the computational burden and improve the imaging quality. Besides, the presented algorithm is much simpler than the existing range CZT approach. Point target simulation validates effectiveness of the presented algorithm.