DocumentCode :
10958
Title :
Processing of Multichannel Sliding Spotlight and TOPS Synthetic Aperture Radar Data
Author :
Wei Xu ; Pingping Huang ; Wang, Ruiqi ; Yunkai Deng
Author_Institution :
Inst. of Electron., Beijing, China
Volume :
51
Issue :
8
fYear :
2013
fDate :
Aug. 2013
Firstpage :
4417
Lastpage :
4429
Abstract :
The inherent limitation between azimuth resolution and range swath width in conventional spaceborne synthetic aperture radar (SAR) systems can be overcome by introducing the displaced phase center antenna technique. In these SAR systems, echoes from all subapertures should be reconstructed and combined together before single-channel SAR processors. However, in the multichannel sliding spotlight and Terrain Observation by Progressive Scans (TOPS) modes, azimuth beam progressive sweeping during the whole acquisition interval leads to that the total Doppler bandwidth spans over several N ·PRF intervals, where N is the number of azimuth channels and PRF is the pulse repetition frequency. As a result, conventional azimuth multichannel reconstruction algorithms for the stripmap mode are not directly suitable for sliding spotlight and TOPS modes. This paper proposes a novel imaging processor for both modes according to their azimuth echo properties. The key point of the proposed focusing processor is the first processing step of multichannel azimuth data reconstruction, which extends the two-step focusing technique to process raw data of the azimuth multichannel case. In addition to azimuth data preprocessing and accurate range cell migration correction steps, the final postprocessing step is added to correct the possible back-folded SAR images. Imaging results on simulated raw data validate the proposed imaging approach.
Keywords :
Doppler radar; image reconstruction; radar antennas; radar imaging; remote sensing by radar; spaceborne radar; synthetic aperture radar; Doppler bandwidth; PRF; SAR system; TOPS synthetic aperture radar data; azimuth beam progressive sweeping; azimuth echo properties; azimuth multichannel reconstruction algorithm; azimuth resolution; back-folded SAR image; final postprocessing step; imaging processor; multichannel azimuth data reconstruction; multichannel sliding spotlight processing; phase center antenna technique; pulse repetition frequency; single-channel SAR processor; spaceborne synthetic aperture radar system; stripmap mode; two-step focusing technique; Azimuth; Bandwidth; Beam steering; Doppler effect; Image resolution; Imaging; Synthetic aperture radar; Multichannel; Terrain Observation by Progressive Scans (TOPS); range migration algorithm (RMA); sliding spotlight; spectrum analysis; synthetic aperture radar (SAR);
fLanguage :
English
Journal_Title :
Geoscience and Remote Sensing, IEEE Transactions on
Publisher :
ieee
ISSN :
0196-2892
Type :
jour
DOI :
10.1109/TGRS.2013.2265306
Filename :
6547704
Link To Document :
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