Forward-looking Multi-channel Synthetic Aperture Radar Imaging and Array Attitude Error Compensation

Abstract

To solve the problem of left-right Doppler ambiguity in forward-looking Synthetic Aperture Radar (SAR) imaging, Forward-Looking Multi-Channel SAR (FLMC-SAR) can achieve Doppler ambiguity resolving imaging through beamforming. However, array deviation angle and time-varying platform attitude errors lead to the mismatch between the space and time characteristics of a target, which affects the Doppler ambiguity resolving imaging performance. This study proposes an FLMC-SAR imaging and array attitude error compensation method. First, the three-dimensional FLMC-SAR array deviation-angle error and time-varying platform attitude error models are established. The mechanism of matching the spatiotemporal characteristics of targets in the two-dimensional spatiotemporal spectrum plane is analyzed. In addition, a representation model is established to study the spatiotemporal characteristics mismatch caused by the array attitude error in the spatiotemporal plane. Thereafter, based on the non-left-right spatial variation of the error, we propose a method of adding an error compensation phase to the back projection function to uniformly compensate the array attitude error of left-right symmetric targets. The results of simulation experiments show that the proposed method can achieve FLMC-SAR array attitude correction and error compensation, enhance the performance of forward-looking Doppler ambiguity suppression, and ensure the azimuth resolution performance of forward-looking imaging.

Keywords

• flmc-sar
• forward-looking imaging
• array attitude error
• doppler ambiguity resolving
• azimuth resolution