波罗的海高精度海洋重力测量数据处理与分析  

High-Accuracy Marine Gravity Measurement Data Processing and Analysis in the Baltic Sea

作　　者：陆飚 钟波[1,2] 罗志才 LU Biao;ZHONG Bo;LUO Zhicai(State Key Laboratory of Geo‑information Engineering,Xi'an 710054,China;School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;MOE Key Laboratory of Fundamental Physical Quantities Measurement,School of Physics,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]地理信息工程国家重点实验室,陕西西安710054 [2]武汉大学测绘学院,湖北武汉430079 [3]华中科技大学物理学院引力中心,湖北武汉430074

出　　处：《武汉大学学报（信息科学版）》2021年第8期1139-1147,共9页Geomatics and Information Science of Wuhan University

基　　金：国家重点研发计划(2018YFC1503503);国家自然科学基金(41974015,42061134007);地理信息工程国家重点实验室开放研究基金(SKLGIE2017-Z-1-2)。

摘　　要：海洋重力测量是海洋地区获取高精度、高分辨率地球重力场信息的重要技术方法。研究了波罗的海地区海洋重力测量数据的处理方法,利用测线交叉点处重力测量观测值建立的漂移函数有效减小了重力仪漂移异常的影响,其测量精度达到了0.5 mGal。2017年,海空重力仪Chekan-AM更新以后,其测量稳定性有了显著提高。数据处理结果表明,搭载在常规科考船DENEB的海洋重力测量精度为0.2 mGal,而首次搭载在渡轮URD的海洋重力测量精度为0.6 mGal。根据波罗的海地区局部大地水准面构建的初步结果,证明了获取的海洋重力测量数据对填补数据空白、检测老旧数据以及提高大地水准面精度等方面具有重要作用,研究结果为未来波罗的海地区建立高精度的统一大地水准面提供了数据基础和技术支持。Objectives:Marine gravimetry is a critical method for obtaining high-precision,high-resolution earth gravity field information in the marine areas.For geoid improvement,the absolute reference of the gravity is of particular interest(in contrast to,e.g.,exploration geophysics,where relative accuracy,or pre-cision,is sufficient).Therefore,a constant drift behavior of the gravimeter and also the reference readings in the harbor are important for this application.Methods:The processing strategy of marine gravimetry in the Baltic Sea is studied.The drift function based on gravity differences at crossover points is used to reduce the influence of the abnormal gravimeter drift and the measurement accuracy reached 0.5 mGal.In 2017,the drift stability of the air-marine gravimeter Chekan-AM is significantly improved after an update.Be-sides,the real measured gravity gradients instead of the normal gravity gradient(0.3086 mGal/m)in the harbors are used to calculate the gravity differences between the Chekan-AM sensor and connection points due to their large altitude differences in the campaign URD2017.Results:The gravimetry data processing results show that the accuracy of the marine gravimetry onboard the conventional research vessel is0.2 mGal and that onboard the ferry is 0.6 mGal.The accuracy reaches the aim of sub-mGal in the project of Finalising Surveys for the Baltic Motorways of the Sea(FAMOS)and is even close to the current highest accuracy level of 0.1–0.2 mGal in marine gravimetry.The preliminary results of the construction of the local geoid in the Baltic Sea region are given,which proves that the obtained marine gravity measure-ment data plays an important role in filling data gaps,verifying old gravity data and improving the accuracy of the regional geoid.Conclusions:Our research provides the foundation of marine gravimetry technologies and gravity data sets for establishing a unified geoid for the entire Baltic region in the future.

关 键 词：海洋重力测量 重力仪Chekan-AM 波罗的海地区 重力仪漂移函数 局部大地水准面 

分 类 号：P223.39[天文地球—大地测量学与测量工程]