Acta Geodaetica et Cartographica Sinica ›› 2019, Vol. 48 ›› Issue (7): 849-861.doi: 10.11947/j.AGCS.2019.20180269

• Geodesy and Navigation • Previous Articles     Next Articles

Spatio-temporal baseline analysis of lunar-based repeat-track SAR interferometry

DONG Jinglong1,2, JIANG Liming1,2, JIANG Houjun1,3, SHEN Qiang1,2, LI Dewei1,2, WANG Hansheng1,2, MAO Song1,2   

  1. 1. State Key Laboratory of Geodesy and Earth's Dynamics, Institute of Geodesy and Geophysics, Chinese Academy of Sciences, Wuhan 430077, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Nanjing University of Posts and Telecommunications, Nanjing 210023, China
  • Received:2018-06-15 Revised:2019-03-28 Online:2019-07-20 Published:2019-07-26
  • Supported by:
    The National Natural Science Foundation of China (Nos. 41590854; 41501497); The State Key Laboratory of Geodesy and Earth's Dynamics (Institute of Geodesy and Geophysics, CAS) Foundation (No. SKLGED2018-5-2-E)

Abstract: Based on the relative motion features of the Earth-Moon system, we constructed the observation geometry of lunar-based repeat-track synthetic aperture radar interferometry (LB-SAR RTI), and calculated the revisit time of lunar-based synthetic aperture radar (LB-SAR) and the corresponding perpendicular baseline by using NASA/JPL ephemeris (DE430). The results show that the revisit period of LB-SAR is about 24.8 h; the length of perpendicular baseline varies greatly with the number of revisits and exhibit a periodic variation about one sidereal month resulting from the varied Moon's N-S velocity. Furthermore, we investigated the features related to the spatio-temporal baselines under the constraint of critical baseline. We find that at a specific time, only part of revisits can be used as temporal baseline, and the revisits suitable as temporal baseline will also vary with the initial observation time. Furthermore, the number of interferometric combinations vary significantly with temporal baseline and the Moon's declination. Near 50% effective interferometric combinations have the temporal baseline near the integer multiples of sidereal month. About 80% effective interferometric combinations occur in regions with the Moon's declination greater than 10°. Therefore, the design of the observation data acquisition plan of LB-SAR RTI should comprehensively take into account the factors related to temporal baseline, spatial baseline and initial observation time.

Key words: lunar-based SAR, repeat-track, JPL ephemeris, temporal baseline, spatial baseline

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