基于ICESat-2多波束激光测高数据的全球海洋重力异常反演分析  

Global marine gravity anomalies recovered from multi-beam laser altimeter data of ICESat-2

作　　者：李真[1] 郭金运[1] 孙中苗 贾永君[3] 黄令勇 孙和平 LI Zhen;GUO Jinyun;SUN Zhongmiao;JIA Yongjun;HUANG Lingyong;SUN Heping(College of Geodesy and Geomatics,Shandong University of Science and Technology,Qingdao 266590,China;State Key Laboratory of Geo-Information Engineering,Xi’an 710054,China;National Satellite Ocean Application Service,Beijing 100081,China;Innovation Academy for Precision Measurement Science and Technology,Chinese Academy of Sciences,Wuhan 430077,China)

机构地区：[1]山东科技大学测绘与空间信息学院,山东青岛266590 [2]地理信息工程国家重点实验室,陕西西安710054 [3]国家卫星海洋应用中心,北京100081 [4]中国科学院精密测量科学与技术创新研究院,湖北武汉430077

出　　处：《测绘学报》2024年第2期252-262,共11页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金(42192535,42274006,42242015)。

摘　　要：卫星测高技术是获取精细海洋重力数据的重要技术手段之一。常规卫星测高反演海洋重力异常主要是利用沿轨测高数据,而跨轨数据因较长的时间间隔或者稀疏的地面轨间距往往不能用于海洋重力异常反演,进而影响了海洋重力异常模型精度的进一步改善。新型激光测高ICESat-2能够同时获得3对光束观测数据,相邻激光束的地面间距约为3 km,为结合跨轨数据改善海洋重力异常模型提供了可能。本文首先给出了集成沿轨和跨轨数据反演海洋重力异常的处理策略;然后,分别利用沿轨数据和集成的数据构建了ICESat-2全球海洋重力异常模型(IS2Gra_alo和IS2Gra_alo_acr),结果表明通过补充跨轨数据能够有效提高沿轨数据反演海洋重力异常的精度,并验证了ICESat-2测高数据反演全球海洋重力异常的可靠性。此外,本文还探讨了ICESat-2不同跨轨数据组合对海洋重力异常模型反演精度的影响,在沿轨数据的基础上集成适当距离的跨轨观测数据能够有利于改善海洋重力异常模型的精度。本文研究为后续SWOT宽刈幅测高数据和我国双星跟飞模式测高数据反演海洋重力异常模型提供了参考意义。Satellite altimetry is one of the crucial techniques for the recovery of marine gravity anomalies.The along-track altimeter data is commonly used,while the cross-track data from conventional altimetry missions is not used to recover marine gravity anomalies due to the long time intervals or sparse ground-track spacing,which limits the improvement of the gravity anomaly model.The ICESat-2 laser altimetry mission operates with three pairs of laser beams,each pair separated by 3 km,which provides the possibility of using the cross-track altimeter data.The cross-track data processing method is presented and global marine gravity anomaly models(named IS2Gra_alo and IS2Gra_alo_acr)are recovered from the along-track altimeter data and the combination of along-track and cross-track altimeter data,respectively.The root mean square(RMS)of the difference between IS2Gra_alo_acr and global shipborne gravity is 5.54 mGal,which is 0.16 mGal better than that of IS2Gra_alo.According to the difference between ICESat-2 gravity models and released global gravity anomaly models,the RMS derived by IS2Gra_alo_acr is at least 0.10 mGal better than that of IS2Gra_alo.The above results confirm that the accuracy of the gravity model recovered from along-track data is improved by incorporating cross-track data,and the ICESat-2 altimeter data is reliable for the recovery of global marine gravity anomalies.Additionally,the combination of different cross-track and along-track altimeter data is discussed for the accuracy of the gravity model recovered from ICESat-2.The accuracy of the gravity model is able to be improved by incorporating the appropriate cross-track altimeter data with the along-track altimeter data.This research provides a reference for the recovery of marine gravity anomalies from the future altimeter data of the SWOT altimetry mission and the two-satellite tandem mode altimetry of China.

关 键 词：ICESat-2 卫星激光测高 海洋重力异常 垂线偏差 海面高 

分 类 号：P228[天文地球—大地测量学与测量工程]