The Uruguayan gravimetric geoid: UruGeoide2007

The Uruguayan gravimetric geoid model UruGeoide2007 was calculated by the Military Geographic Service (SGM) in 2007. The extent is from 29° S to 36° S in latitude and 52° W to 60° W in longitude, with a grid resolution of 1´ x 1´. The geodetic reference system is WGS84. The computation was based on the remove-restore procedure, using 8433 gravity observations from stations in Argentina, Brasil and Uruguay, 9172 marine free-air gravity anomalies from the KMS02 model, the GGM02C geopotential model, the SRTM terrain model and the DNSC05 bathymetric model. The reduced height anomalies were computed from the reduced gravity anomalies by Stokes integration via spherical Fast Fourier Transform. After adding back the residual terrain model effects and the contribution of the global geopotential model, the obtained quasi-geoid was transformed into a geoid model by using a Bouguer anomaly grid, even if the difference between the two models is 1 cm at most.

The geoid model is provided in ISG format 2.0 (ISG Format Specifications), while the file in its original data format is available at the model ISG webpage.

乌拉圭重力大地水准面模型UruGeoide2007由军事地理服务局（Military Geographic Service，SGM）于2007年完成计算。模型覆盖纬度范围为南纬29°至36°，经度范围为西经52°至60°，网格分辨率为1′×1′。采用的大地基准参考系统为WGS84。本次计算采用移去-恢复法（remove-restore procedure），所用数据包括：阿根廷、巴西与乌拉圭境内测站的8433组重力观测值，源自KMS02模型的9172个海洋自由空气重力异常，GGM02C重力位模型，SRTM地形模型以及DNSC05水深地形模型。研究人员借助球面快速傅里叶变换（Fast Fourier Transform，FFT）完成的斯托克斯积分，由归算重力异常计算得到归算高程异常。在回加残余地形模型影响与全球重力位模型贡献项后，所得到的似大地水准面通过布格异常网格转换为大地水准面模型——尽管两类模型间的最大差值仅为1厘米。该大地水准面模型以ISG格式2.0（ISG格式规范）发布，原始数据格式的文件可在该模型的ISG官方网页获取。