第 3 卷第 5 期 雷 达 学 报 Vol. 3No. 5
2014 年 10 月 Journal of Radars Oct. 2014
Channel Error Compensation for Multi-channel SAR
Based on Cost Function
Zhang Lei
*①②
Deng Yun-kai
①
Wang Yu
①
Zheng Shi-chao
①②
Yang Liang
①②
①
(Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China)
②
(University of Chinese Academy of Sciences, Beijing 100049, China)
Abstract: Multi-channel in azimuth is a technique to achieve high-resolution as well as wide-swath in Synthetic
Aperture Radar (SAR) systems. Channel error is inevitable in multi-channel systems and it induces blurring in
subsequent SAR imagery. Existing compensation approaches are sensitive to system parameters as well as the
imaging scenes. Uncertainty of the parameters impacts the validation of these algorithms. In this paper, an
improved approach is presented to remove the channel error. Based on the error form, this approach models
channel error as three parts: the range gain error, the pulse sampling clock error, and the transmission phase error.
The range gain error and the pulse sampling clock error are removed alternately. Then the proposed approach uses
cost function to estimate the transmission phase error so that it is independent from the imaging scene. Point
target simulations are carried out to investigate the performance, and real data comparison experiments are carried
out to verify this approach.
Key words: Synthetic Aperture Radar (SAR); Multi-channel; Channel error compensation
CLC index: TN957.52
DOI: 10.3724/SP.J.1300.2014.14052
基于代价函数的通道误差校正方法
张 磊
①②
邓云凯
①
王 宇
①
郑世超
①②
杨 亮
①②
①
(中国科学院电子学研究所 北京 100190)
②
(中国科学院大学 北京 100049)
摘 要:方位多通道技术是合成孔径雷达(SAR)实现高分宽测的手段之一。在多通道系统中通道失配是不可避免的,
这会导致 SAR 图像模糊。已有的通道失配校正方法大多依赖于系统参数以及场景内容。参数的不确定性将会大大
降低校正算法的稳定性。该文提出了一种改进的通道失配校正方法,根据失配产生的原因,将通道失配分为距离增
益误差、脉冲采样时钟误差和传输相位误差 3 项。前两项误差通过交替估计进行补偿,而传输相位误差则通过代价
函数给予估计。该方法对成像场景的依赖较小,基于机载多通道验证平台实测数据的实验验证了该方法的有效性。
关键词:合成孔径雷达(SAR);多通道;通道误差校正
中图分类号:TN957.52 文献标识码:A 文章编号:2095-283X(2014)05-0556-09
1 Introduction
Synthetic Aperture Radar (SAR) is a widely
used remote sensing instrument. High-resolution as
well as wide-swath is one of the main goals of
system design
[1,2]
. For conventional spaceborne SAR,
high resolution in azimuth requires large Doppler
Manuscript received March 19, 2014; revised July 8, 2014.
Published online September 12, 2014.
Supported by the National Natural Science Foundation of China
(No. 61172122, 61422113).
*Corresponding author: Zhang Lei
E-mail: 314forever@163.com
bandwidth, which means a high Pulse Repetition
Frequency (PRF) to avoid ambiguity. However,
wide imaging swath requires wide range beam,
hence PRF must be low to guarantee the echo
integrality. This contradiction is known as the
minimum-antenna-area constraint
[3]
.
Multi-channel technique was proposed to
break through this constraint. Multi-channel can
be realized either in the range direction
[4]
or in the
azimuth direction, even in both directions
[5,6]
.
Besides, channels can be placed either on single
platform or distribute platforms
[7,8]
. Multi-channel
in azimuth on single platform has been tested with