Study On The Quenching And Error Analysis Of Regional Quasi - Geoid In Plateau Area

With the continuous development and application of GNSS technology, the continuous improvement of gravity measurement technology and the continuous development of satellite gravity technology etc, it promotes the vigorous development of the surveying and mapping technology and the continuous improvement of the measuring means, which makes the surveying and mapping industry take place the variety of the continuous changes. How to get earth geospatial information becomes the issue geodetic scholars concern, and quasi-geoid is the elevation datum to obtain geospatial information, thus determining the high-resolution, high-precision regional quasi-geoid becomes the issue the geodetic workers research today. In the process of refining quasi-geoid, using the latest earth gravity model, high-precision and high-resolution digital terrain model and the result data of uniform distribution gravity point, which combined with the result data of the regional high-precision GPS/leveling points, through the advanced computing technology to building the high-precision, high-resolution regional quasi-geoid model. The continuous refinement of the high-precision, high-resolution regional quasi-geoid model promotes the process of the construction of modern surveying and mapping reference, which provides the strong technical support to constructive "Digital Earth", "Digital City" etc, at the same time which provides the strong guarantee to the engineering surveying field of transport and water, the construction of local coordinate system and emergency surveying and mapping reference of the natural disasters, which plays an important role to the establishment of digital elevation datum.This paper describes the basic theories and methods of the regional quasi-geoid refinement and the applied research of EGM2008 earth gravity field model and remove-restore method; simply describes several kinds of the mathematical fitting model in the process of the regional quasi-geoid refinement; seriously introduces the process of establish the regional quasi-geoid refinement model in the the southwestern region as well as makes the corresponding improvement to a few minor problems related to the regional quasi-geoid refinement model; which combines the GPS/leveling data in the southwest plateau test area and the latest EGM2008 model, adopt polynomial fitting, multi-faceted function fitting, weighted average fitting and moving surface fitting to establishing the regional quasi-geoid model, writes applet through the C# high-level programming language to calculate the test data and analysis the accuracy of the result. Aimed at the error of calculating, the paper seriously introduces the influence of several error sources in the accuracy of the regional quasi-geoid refinement. On this basis, the paper analysis and discuss some problems in the process of the high-precision, high-resolution regional quasi geoid refinement, draws some useful conclusions and recommendations on the measurement projects.