Autonomous Navigation Airborne Forward-Looking SAR High Precision Imaging with Combination of Pseudo-Polar Formatting and Overlapped Sub-Aperture Algorithm

Remote Sensing

Xueming Peng¹  Yanping Wang¹  Wen Hong¹  Weixian Tan¹ 

[1] Science and Technology on Microwave Imaging Laboratory (MITL), Institute of Electronics, Chinese Academy of Sciences (IECAS), No. 19, North 4th Ring West, Beijing 100190, China; E-Mails:

关键词: autonomous navigation airborne forward looking SAR;    pseudo-polar formatting;    overlapped sub-aperture algorithm;    radar imaging;   

DOI  :  10.3390/rs5116063

来源: mdpi

【 摘 要 】

Autonomous navigation airborne forward-looking synthetic aperture radar (SAR) observes the anterior inferior wide area with a short cross-track dimensional linear array as azimuth aperture. This is an application scenario that is drastically different from that of side-looking space-borne or air-borne SAR systems, which acquires azimuth synthetic aperture with along-track dimension platform movement. High precision imaging with a combination of pseudo-polar formatting and overlapped sub-aperture algorithm for autonomous navigation airborne forward-looking SAR imaging is presented. With the suggested imaging method, range dimensional imaging is operated with wide band signal compression. Then, 2D pseudo-polar formatting is operated. In the following, azimuth synthetic aperture is divided into several overlapped sub-apertures. Intra sub-aperture IFFT (Inverse Fast Fourier Transform), wave front curvature phase error compensation, and inter sub-aperture IFFT are operated sequentially to finish azimuth high precision imaging. The main advantage of the proposed algorithm is its extremely high precision and low memory cost. The effectiveness and performance of the proposed algorithm are demonstrated with outdoor GBSAR (Ground Based Synthetic Aperture Radar) experiments, which possesses the same imaging geometry as the airborne forward-looking SAR (short azimuth aperture, wide azimuth swath). The profile response of the trihedral angle reflectors, placed in the imaging scene, reconstructed with the proposed imaging algorithm and back projection algorithm are compared and analyzed.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland