珠峰峰顶大地水准面高的确定
Determination of Geoid Height at the Summit of Mount Qomolangma
郭春喜 1党亚民 2郭鑫伟 1王斌 1刘晓云 1王夏莉1
作者信息
- 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
- 折叠
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士0.06)m,计算结果较2005年更加可靠.
Abstract
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 air-borne 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.Final-ly,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Key words
Mount Qomolangma/airborne gravity/quasi-geoid/remove-restore method/geoid height引用本文复制引用
基金项目
国家自然科学基金(41774004)
国家自然科学基金(41904040)
陕西测绘地理信息局科技创新项目(SCK2022-03)
出版年
2024
NETL
NSTL
万方数据