顾及地形效应的地面重力向上延拓模型分析与检验  

Test and Analysis of Upward Continuation Models for Earth Surface Gravity with Regard to the Effect of Topographic Height

作　　者：刘敏[1,2] 黄谟涛[2] 邓凯亮[2,3] 欧阳永忠[2] 翟国君[2] 吴太旗[2] 

机构地区：[1]信息工程大学地理空间信息学院,河南郑州450001 [2]海洋测绘研究所,天津300061 [3]国防科学技术大学机电工程与自动化学院,湖南长沙410073

出　　处：《武汉大学学报（信息科学版）》2018年第1期112-119,共8页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41474012,41374018);国家重大科学仪器设备开发专项(2011YQ12004503);国家基础研究计划(613219)~~

摘　　要：重力向上延拓在外部重力场逼近和航空重力测量数据质量评估中具有重要应用。本文深入分析研究了6种向上延拓计算模型的技术特点和适用条件,提出了应用超高阶位模型加地形改正、点质量方法结合移去-恢复技术实现＂先向下后向上延拓＂计算的实施策略,探讨了计算过程特别是前端向下延拓过程的稳定性问题。通过实际数值计算,定量评估了地形质量对不同高度向上延拓结果的影响,对比分析了不同向上延拓模型顾及地形效应的实际效果,同时对向上延拓模型计算精度进行了估计。在地形变化比较激烈的山区,地形质量对向上延拓结果的影响最大可达几十个mGal（10^（-5） m·s^（-2））,当计算高度为10km时,该项影响超过3mGal;向上延拓计算模型误差（不含数据误差影响）一般不超过1mGal;基于超高阶位模型和地形改正信息实施向下延拓过渡的布阿桑（Poisson）积分向上延拓模型,具有计算过程简便、计算结果稳定可靠等优点。Upward continuation plays an important role in approximation of the external gravity field of the earth and in accuracy evaluation of airborne gravity data.This paper reviews the available models for upward continuation including approximate spherical solution and rigorous formulas,and makes a comprehensive comparison and analysis of their properties as well as the applicability of different models.The Ultra-high-degree geopotential model and point mass methods are suggested to be used for the realization of＂downward continuation comes before upward＂procedure combining the remove-restore technique,paying attention to the stability of the downward continuation solution before the upward continuation.Real numerical computations were carried out to evaluate the effects of topographic height on upward continuations.The performance of different models with regard to the effect of topographic height were compared and analyzed.The accuracy of the upward continuation model was estimated.Some useful conclusions are obtained.in rugged mountainous areas,the maximum rms value of terrain effect on upward continuation can reach several tens mGal（10^（-50 m/s^2）.Even if the continuation height is greater than 10 km,the effect of topographic height on upward continuation can exceed 3 mGal.The accuracy of upward continuation model was estimated to be about±1 mGal.The modified Poisson integral model,in which the downward continuation is accomplished using a ultrahigh-degree geopotential model and terrain information,is therefore recommended for upward continuation due to its simple computation procedure,high stability,and reliability.

关 键 词：重力测量 向上和向下延拓 地形效应 移去-恢复技术 超高阶位模型 点质量模型 

分 类 号：P223[天文地球—大地测量学与测量工程]