测绘学报 ›› 2014, Vol. 43 ›› Issue (9): 917-923.doi: 10.13485/j.cnki.11-2089.2014.0124

• 学术论文 • 上一篇    下一篇

大气折射率时间变化对地球同步轨道圆迹SAR聚焦性能的影响

寇蕾蕾1,向茂生2   

  1. 1. 南京信息工程大学
    2. 中国科学院电子学研究所
  • 收稿日期:2014-01-03 修回日期:2014-06-23 出版日期:2014-09-20 发布日期:2014-09-25
  • 通讯作者: 寇蕾蕾 E-mail:cassie320@163.com
  • 基金资助:

    地球同步轨道圆迹SAR重轨干涉技术监测地表三维形变

Effect of Temporal Variation of Atmospheric Refraction on Geosynchronous Circular SAR Focusing Performance

KOU Leilei1,XIANG Maosheng2   

  1. 1. Nanjing University of Information Science and Technology
    2. Institute of Electronics, Chinese Academy of Science
  • Received:2014-01-03 Revised:2014-06-23 Online:2014-09-20 Published:2014-09-25
  • Contact: KOU Leilei E-mail:cassie320@163.com

摘要:

结合了圆迹SAR(CSAR)和地球同步轨道SAR(GEOSAR)的特点,地球同步轨道圆迹SAR(GEOCSAR)具有大面积区域观测、可获得目标三维信息、可对目标区域连续监测等优点。但GEOCSAR合成孔径时间长,完成整个圆周孔径测量的时间为24小时,而大气变化的时间尺度经常表现为数分钟到数小时,因此大气折射率时间变化将会对GEOCSAR方位向聚焦成像产生重要影响。本文考虑L波段GEOCSAR,因此对流层和电离层效应均不可忽略。文中建立了对流层和电离层折射率时间变化引起的相位误差模型,分析和推导了折射率时间变化对GEOCSAR方位向聚焦性能的影响,计算了引起L波段GEOCSAR聚焦性能退化的最小对流层折射率和电离层电子含量随机时间变化量,并通过仿真进行了验证。

关键词: 地球同步轨道圆迹SAR(GEOCSAR), 大气折射率, 时间变化, 对流层, 电离层

Abstract:

Combining the geosynchronous SAR (GEOSAR) with the circular SAR (CSAR), the geosynchronous circular SAR (GEOCSAR) has many advantages such as broad coverage, high resolution three dimensional (3D) imaging and continuous surveillance. However, due to its very long synthetic aperture time (about 24 hours for full aperture measurement), the effect of the atmospheric temporal variation may be significant, for the atmosphere usually changes its structures on timescales of minutes to hours. Since this paper considers the L-band GEOCSAR system, the tropospheric and ionospheric effects should both be included. The phase error due to the temporal variation of the tropospheric and ionospheric refraction is modeled. Then, the effect of the temporal variation of the troposphere and ionosphere on GEOCSAR imaging is derived and analyzed. Besides, the minimum of the random tropospheric and ionospheric temporal variation causing the L-band GEOCSAR imaging performance deterioration is deduced. The effects of atmospheric temporal variation are validated via simulations.

Key words: geosynchronous circular SAR (GEOCSAR), atmospheric refraction, temporal variation, troposphere, ionosphere

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