DocumentCode :
70062
Title :
Focusing highly squinted data with motion errors based on modified non-linear chirp scaling
Author :
Gaogao, Liu ; Li, Peng ; Tang, Song ; Zhang, Leiqi
Author_Institution :
Key Laboratory of Electronic Information Countermeasure and Simulation Technology Ministry of Education, Xidian University, Xi´an, Shaanxi, People´s Republic of China
Volume :
7
Issue :
5
fYear :
2013
fDate :
Jun-13
Firstpage :
568
Lastpage :
578
Abstract :
The motion compensation (MOCO) plays a significant role to accommodate the motion errors caused by atmosphere turbulence and/or aircraft maneuvers in airborne synthetic aperture radar configurations. In broadside or small squint cases, the well-focused image can be obtained by the typical two-step MOCO to have the quadratic motion errors compensated. However, with the increasing of squint angle, not only the high-order motion errors, but also the azimuth-variant errors must be taken into account. In this study, a modified non-linear chirp scaling (MNLCS) algorithm is proposed to handle this problem in highlysquinted case. The key is to use the method of series reversion to cover the high-order motion errors, the MNLCS to precondition the data to process the azimuth-variant components and a series expansion to obtain an accurate form of the signal spectrum. The skewed spectrum in highly-squinted case is reduced through the use of a linear range cell migration correction. The simulated results have shown the MNLCS algorithm can handle data with more complicated geometries than the previous algorithm.
fLanguage :
English
Journal_Title :
Radar, Sonar & Navigation, IET
Publisher :
iet
ISSN :
1751-8784
Type :
jour
DOI :
10.1049/iet-rsn.2012.0134
Filename :
6574790
Link To Document :
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