Capella Polar Format Processor with Terrain Correction Jisu Ryua

Abstract:
Polar Format Algorithm (PFA) approximates de-chirped Linear FM (LFM) SAR signal as a manifestation of Fourier projection-slice theorem. This approximation reduces computational complexity of PFA compared to conventional backprojection (CBP) algorithm at the cost of processing flexibility. One example is a depth-of-focus (DOF) phase error that shows up for targets out of image focus plane with non-planar data collection geometry common for space-borne systems. Here, we demonstrate terrain correction algorithm for PFA via post-processing phase error correction that can be calculated pixel-by-pixel basis. The terrain correction is incorporated into Capella’s general PFA spatially-variant phase correction workflow with minimal additional computation.