Acta Geodaetica et Cartographica Sinica ›› 2014, Vol. 43 ›› Issue (9): 917-923.doi: 10.13485/j.cnki.11-2089.2014.0124

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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

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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