An Extended Nonlinear Chirp-Scaling Algorithm for Focusing Large-Baseline Azimuth-Invariant Bistatic SAR Data

For an azimuth-invariant bistatic synthetic aperture radar (BiSAR), not only is the secondary range compression dependent on range, but also the range-cell migration in the range-Doppler domain is nonlinearly dependent on range. To get a better focusing performance, the two range-dependent factors must be taken into account in an imaging algorithm. In this letter, a nonlinear chirp-scaling algorithm is extended for focusing the BiSAR data under a large baseline and a wide range swath. This algorithm leads to more effective processing with computational efficiency, and no interpolation is required.