月基SAR重复轨道干涉测量时-空基线分析  

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

作　　者：董景龙 江利明[1,2] 蒋厚军 沈强 李德伟[1,2] 汪汉胜[1,2] 毛松 DONG Jinglong;JIANG Liming;JIANG Houjun;SHEN Qiang;LI Dewei;WANG Hansheng;MAO Song(State Key Laboratory of Geodesy and Earth’s Dynamics,Institute of Geodesy and Geophysics,Chinese Academy of Sciences,Wuhan 430077,China;University of Chinese Academy of Sciences,Beijing 100049,China;Nanjing University of Posts and Telecommunications,Nanjing 210023,China)

机构地区：[1]中国科学院测量与地球物理研究所大地测量与地球动力学国家重点实验室,湖北武汉430077 [2]中国科学院大学,北京100049 [3]南京邮电大学,江苏南京210023

出　　处：《测绘学报》2019年第7期849-861,共13页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(41590854;41501497);大地测量与地球动力学国家重点实验室开放基金(SKLGED2018-5-2-E)~~

摘　　要：本文根据地-月相对运动特征,建立了月基重轨InSAR观测几何模型,使用NASA/JPL高精度DE430月球星历数据,计算了月基SAR的重访时间以及对应的空间基线。结果表明:月基SAR的重返周期约24.8h;由于月球南北向速度发生周期性变化,月基重轨InSAR垂直基线长度会随重访次数产生较大变化,且基线长度近似呈现1恒星月周期变化特征。在空间基线约束下,本文进一步分析了月基重轨InSAR时-空基线特征,研究发现:①在确定的初始观测条件下,只能在特定的时间基线上实现月基重轨InSAR观测,并且初始观测时间不同,可实现月基重轨InSAR观测的时间基线也不同;②不同的时间基线可形成干涉组合个数不同,约50%的干涉组合个数对应的时间基线接近1恒星月及其整数倍;不同的观测位置可形成干涉组合个数不同,约80%的干涉组合个数发生在月球赤纬大于10°区域。因此,月基重轨InSAR观测数据获取计划的设计应综合考虑时间基线、空间基线以及初始观测时间等因素。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.

关 键 词：月基SAR 重复轨道 JPL星历 时间基线 空间基线 

分 类 号：P237[天文地球—摄影测量与遥感]