The UNLP hybrid quasi-geoid of Tierra del Fuego

This is a combined (gravimetric/geometric) quasi-geoid model for almost the whole province of Tierra del Fuego, computed by means of the Equivalent Source Technique (EST) and the remove-restore technique. The geodetic reference frame is TDF08. The EIGEN-GL04c global gravity model up to degree and order 200 is used to remove the long wavelength part of the spectrum, while the residual terrain correction is based on the SRTM3 digital elevation model. The integration of gravimetric and GPS/levelling data for the computation of the quasi-geoid model is performed by EST, which is basically an inverse gravimetric problem for the estimation of a proper set of point masses. A cross-validation procedure over a set of height anomalies shows a 5 cm error r.m.s. for most of the Argentine part of the island, with larger errors in the Chilean side (up to about 20 cm). The model is here provided with a spatial resolution of 1.5 km.

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.

本数据集为几乎覆盖整个火地岛省的组合式（重力测量/几何）拟大地水准面模型（quasi-geoid model），采用等效源技术（Equivalent Source Technique, EST）与移去-恢复技术（remove-restore technique）解算得到。其大地基准框架为TDF08。采用阶次截至200的EIGEN-GL04c全球重力模型移除频谱的长波长分量，残余地形改正则基于SRTM3数字高程模型（SRTM3 digital elevation model）。本次拟大地水准面模型的解算通过等效源技术实现重力测量与GPS/水准数据的融合，该技术本质上为用于估算合理点质量集的反重力问题。对一组高程异常值（height anomalies）开展交叉验证的结果表明，该岛阿根廷境内多数区域的误差均方根为5厘米，智利一侧误差更大，最高可达约20厘米。本模型的空间分辨率为1.5 km。

该大地水准面模型以ISG格式2.0（ISG格式规范）提供，原始数据格式的文件可在该模型的ISG官方网页获取。