陆探一号卫星SAR载荷关键技术  

Key technologies for spaceborne SAR payload of LuTan-1 satellite system

作　　者：邓云凯 王宇 刘开雨 欧乃铭 刘大成 张衡 王吉利 DENG Yunkai;WANG Yu;LIU Kaiyu;OU Naiming;LIU Dacheng;ZHANG Heng;WANG Jili(Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]中国科学院空天信息创新研究院,北京100190

出　　处：《测绘学报》2024年第10期1881-1895,共15页Acta Geodaetica et Cartographica Sinica

基　　金：国家重点研发计划(2017YFB0502700);国家自然科学基金(61825106,61901443,62001451)。

摘　　要：陆探一号是我国首个采用差分干涉测量技术实现地表形变监测应用的合成孔径雷达(SAR)卫星星座,其01组双星分别于2022年1月26日和2022年2月27日成功发射并在轨运行。双星在轨后具有双基编队干涉和双星组网两种模式。在双星干涉成像模式下,利用双基InSAR条带模式获取全国高精度DEM;在双星组网成像模式下,双星同轨道间隔180°在轨稳定运行,重访周期由8 d下降至4 d,获取时序相干数据,具备高精度地表形变监测的能力。此外,陆探一号SAR系统具备多模式极化优势,可获取单航过多极化InSAR、混合极化SAR数据,可用于林业、国土资源调查及灾害监测等。本文对陆探一号SAR载荷的关键技术,包括相位同步、模糊抑制与系统定标等进行系统性阐述和分析。陆探一号SAR载荷实现的最高分辨率为3 m,最大幅宽可达400 km,同时干涉模式方位模糊度优于-20 dB,系统性能优良,本文通过地面测试和在轨实测数据对陆探一号多模式成像性能进行验证。LuTan-1(referred as LT-1)is China s first civil synthetic aperture radar(SAR)satellite mission to monitor the ground deformation with high precision by differential interferometry technology.The LT-1A and LT-1B have been success-fully launched on January 26 and February 27,2022,respectively.The data acquisition schedule of LT-1 mission is divided into two stages,which corresponding to two specific orbit configurations.In the first stage,two satellites fly in a compact formation to get the digital elevation model(DEM)using the bistatic InSAR strip mode.In the second stage,both satellites fly in a common reference orbit with 180°separation.The revisit time of the individual satellite is 8 days,and it can be reduced to 4 days with two satellites.LT-1 satellite constellation can stably obtain time series data,so that we can monitor the ground deformation with high precision.Moreover,the multi-mode polarimetric payload will be utilized to obtain single-pass multi-polarimetric InSAR and hybrid polarimetric SAR data for forestry,land resource surveys,disaster monitoring,etc.In this paper,the key technologies of the LT-1 SAR payload,including phase synchronization,ambiguity suppression and system calibration,are systematically described and analyzed.The maximum resolution of LT-1 is 3 m,and the maximum swath width is 400 km,respectively.The azimuth ambiguity-to-signal ratio(AASR)of the interference wave position is better than-20 dB.The performance is partially demonstrated by ground testing and on-orbit actual measurement data.

关 键 词：陆探一号 相位同步 系统定标 极化SAR 模糊抑制 

分 类 号：P237[天文地球—摄影测量与遥感]