A modified Phase Gradient Autofocus (PGA) algorithm for Airborne/Stationary Bistatic Synthetic bistatic SAR imaging

作者：Zhou Song^*; Bao Min; Chen Shi Chao; Xing Meng Dao; Bao Zheng

来源：Journal of Electronics and Information Technology, 2013, 35(6): 1456-1463.

DOI：10.3724/SP.J.1146.2012.00689

• Airborne/Stationary (A/S) configuration
• Auto-focus
• Bistatic sar imaging
• Bistatic synthetic aperture radar
• Phase gradient
• Quadratic phase
• Range cell migration correction
• Translational invariance

In Airborne/Stationary Bistatic Synthetic Aperture Radar (A/S-BiSAR), the assumption of translational invariance is no longer available. After the Range Cell Migration Correction (RCMC), the range compressed signal in the same range gate exhibits azimuth-variant Doppler rates which make the phase error difficult to be estimated from the echoes by using the available Phase Gradient Autofocus (PGA) algorithms. To deal with this problem, a modified PGA algorithm is proposed. Comparing with the traditional PGA, the Residual Quadratic Phase (RQP) caused by the azimuth-variant Doppler rates is additionally estimated and compensated. As the influence of the azimuth-variant Doppler rates is greatly reduced, a phase gradient estimator is subsequently applied to accurate phase error retrieval. Furthermore, the range-variance of the phase error is also concerned in the phase error estimation and correction, thus the proposed algorithm is suitable for A/S-BiSAR with wide swath in range. Raw data experiments are presented to verify the advantages of the proposed algorithm.

• 出版日期2013
• 单位西安电子科技大学