Please use this identifier to cite or link to this item: https://hdl.handle.net/10356/86580
Title: Coherent auto-calibration of APE and NsRCM under fast back-projection image formation for airborne SAR imaging in highly-squint angle
Authors: Yang, Lei
Zhou, Song
Zhao, Lifan
Xing, Mengdao
Keywords: Auto-calibration
Squint Synthetic Aperture Radar (SAR)
Issue Date: 2018
Source: Yang, L., Zhou, S., Zhao, L., & Xing, M. (2018). Coherent auto-calibration of APE and NsRCM under fast back-projection image formation for airborne SAR imaging in highly-squint angle. Remote Sensing, 10(2), 321-.
Series/Report no.: Remote Sensing
Abstract: Synthetic Aperture Radar (SAR) imaging with a non-zero (forward) squint angle is capable of providing a longer time for reaction than that of the broadside mode. However, due to the large squint angle, there will be severe coupling between range and azimuth samples in the echoed data, which is known as the problematic Range Cell Migration (RCM) in the SAR community. Especially when the SAR sensor mounted on an airborne platform encounters unexpected motion deviations/errors, the coupling becomes more complicated, and it is difficult to differentiate the systematic RCM for the SAR Image Formation Processing (IFP) and the non-systematic RCM error to be compensated. To this end, a novel and accurate SAR imaging algorithm is proposed in this paper to facilitate the processing of airborne SAR data collected at a high-squint angle. Firstly, the proposed algorithm is established under a Fast Time-Domain Back-Projection (FTDBP) framework for the SAR IFP. FTDBP paves the way to avoid the complicated processing for the systematic RCM as for the conventional SAR IFP in the Doppler processing manner. It is capable of generating a high-resolution SAR image efficiently under more general geometries and configurations. Secondly, regarding the non-systematic RCM errors, the proposed algorithm realizes the compensation by correcting both the Non-systematic Range Cell Migration (NsRCM), as well as Azimuthal Phase Error (APE) in a coherent manner. It is consequently capable of auto-calibrating the effects of the motion error completely without being dependent on the airborne navigation unit. Finally, both simulated and raw data collected by the airborne squinted SAR are applied to evaluate the proposed algorithm. Comparisons with conventional algorithms are carried out to reveal the superiority of the proposed algorithm.
URI: https://hdl.handle.net/10356/86580
http://hdl.handle.net/10220/45328
ISSN: 2072-4292
DOI: 10.3390/rs10020321
Rights: © 2018 The Author(s). Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
Fulltext Permission: open
Fulltext Availability: With Fulltext
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