珠峰峰顶大地水准面高的确定  

Determination of Geoid Height at the Summit of Mount Qomolangma

作　　者：郭春喜 党亚民[2] 郭鑫伟 王斌 刘晓云 王夏莉 GUO Chunxi;DANG Yamin;GUO Xinwei;WANG Bin;LIU Xiaoyun;WANG Xiali(Geodetic Data Processing Centre of Ministry of Natural Resources,Xi'an 710054,China;Chinese Academy of Surveying and Mapping,Beijing 100830,China)

机构地区：[1]自然资源部大地测量数据处理中心,陕西西安710054 [2]中国测绘科学研究院,北京100830

出　　处：《武汉大学学报（信息科学版）》2024年第3期434-441,共8页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41774004,41904040);陕西测绘地理信息局科技创新项目(SCK2022-03)。

摘　　要：大地水准面高是珠峰正高确定的前提,通过计算珠峰似大地水准面(高程异常)以及似大地水准面与大地水准面间的高差确定大地水准面高。首先,利用地形模型、地球重力场模型、地面和航空融合重力数据等资料,基于Molodensky原理及移去-恢复技术精化珠峰地区分辨率为1.5′×1.5′的重力似大地水准面模型;其次,利用珠峰地区GNSS水准点纠正重力似大地水准面模型,消除系统差,得到1985国家高程基准下珠峰区域的似大地水准面模型;最后,利用珠峰峰顶实测重力值,采用移去-恢复和重力归算方法计算似大地水准面与大地水准面间的高差,完成珠峰峰顶大地水准面高的计算。结果表明,基于EIGEN-6C4地球重力场模型,融合地面、航空重力获得的重力似大地水准面精度达4.8 cm,相较于单独利用地面重力资料获得模型精度提升约40%;在1985国家高程基准下,珠峰峰顶高程异常为-25.586 m,似大地水准面与大地水准面间的高差为-1.216 m,大地水准面高为(-26.802±0.06)m,计算结果较2005年更加可靠。Objectives:The determination of the orthometric height of Mount Qomolangma requires the prior calculation of geoid height,which is determinined by the quasi-geoid(height anomaly) and the height difference between the quasi-geoid and geoid.Methods:First,based on Molodensky principle and remove-restore technology,a 1.5'×1.5' gravity quasi-geoid model in Mount Qomolangma region can be established by using a terrain model,an earth gravity field model,and the fusion data of ground and airborne gravity.Then,system errors can be eliminated by correcting the gravity quasi-geoid model with GNSS-leveling points.The quasi-geoid based on the National Vertical Datum 1985 can be obtained.Finally,the height difference between the quasi-geoid and geoid can be calculated by using the remove-restore method by gravity at the summit of Mount Qomolangma.Results:The results show that the EIGEN-6C4 earth gravity field model performs best in the region of Mount Qomolangma compared to EGM2008 and XGM2019e_2159.The precision of the gravity geoid model is 7.8 cm based solely on the EIGEN-6C4 and ground gravity data,while it is 4.8 cm based on the EIGEN-6C4 and the fusion data of ground and airborne gravity.The accuracy of model is improved by approximately 40% than using ground gravity data only.At the summit of Mount Qomolangma,the height anomaly is -25.586 m,the height difference between the quasi-geoid and geoid is -1.216 m,and the geoid height is(-26.802±0.06) m in the National Height Datum 1985.Conclusions:Airborne gravity can effectively provide data for the region where ground gravity data is sparse or non-existent.By incorporating airborne gravity,the density of gravity data at the summit of Mount Qomolangma has been greatly improved,leading to an increased accuracy of the quasi-geoid model.The availability of richer data,more accurate models,and more advanced calculation methods in 2020 resulted in more reliable results compared to the 2005 measurement.

关 键 词：珠穆朗玛峰 航空重力 似大地水准面 移去-恢复方法 大地水准面高 

分 类 号：P223[天文地球—大地测量学与测量工程]