Chirp scaling algorithm for processing bistatic SAR data based on Loffeld's Bistatic Formula

摘要

This paper discusses bistatic synthetic aperture radar processing using the chirp scaling algorithm in the azimuth-invariant configuration. The analytical two-dimensional signal spectrum introduced by Loffeld (Loffeld's Bistatic Formula: LBF) is used. LBF consists of two key phase terms, the first one being a quasi-monostatic (QM) term similar to the monostatic phase of a point target, and the second phase is a bistatic deformation (BD) term which is an intrinsic feature of the bistatic geometry, and is due to the separation between the transmitter and receiver platforms. In this paper, both phase terms are combined into a single phase. Next, the key components of the signal including the azimuth modulation, range cell migration (RCM), and range-azimuth coupling are derived using a Taylor series expansion. These terms can then be dealt with using the conventional processing techniques. In the current paper, chirp scaling is used to remove the RCM in two steps, as in the monostatic case. Finally, simulation results are provided to validate the approach.