ISG

   International Service for the Geoid

   

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Services - Software download




Geoid School

CD International Geoid School
for Determination and Use of the Geoid 1994-2010
(with program and exercises)

ON DEMAND
Matlab ISG format utilities

Matlab functions to read and write geoid/quasi-geoid models in ISG format. The reader is able to read all the versions of the format (v 1.0, v 1.01 and v 2.0), while the writer can write models only according to the newest v 2.0 of the format, since the older ones are deprecated.

The zip package contains the two functions and an example on their usage

download
Harmonic Manipulator HD

Spherical Harmonics Manipulator

Software supported by the Italian Space Agency through the GOCE-Italy project (rif. dr. tec-001-GOCEI-1.0)

download
ELGRAM
Ellipsoidal Gravity Model Manipulator

Source code (fortran 77) for evaluating at sparse points or an a grid the following functionals

  • geoid ondulations 
  • gravity anomalies 
  • components of deflection of the vertical

using ellipsoidal global model coefficients (Nmax= 360) developed in ellipsoidal harmonic functions (derived from global model EGM96)

source code

coefficients

TcLight

Program to compute terrain effects on gravimetric quantities

(source and example file windows zip)

readme

source code

examples

ISGFormatHandler

Python package for geoid file format conversion

download

GeoidLab

open-source Python package (GPL-3.0) designed for gravity-field analysis and high-accuracy regional gravimetric geoid computation using the remove-compute-restore technique. It provides a complete, automated pipeline including gravity reductions, terrain corrections, and Stokes' kernel integration (with 3 modifications). The software supports automatic downloads of GGMs from ICGEM and various DEMs. It features a clean CLI with a configuration file, comprehensive documentation, and is accompanied by the following publication:

C. Kelly, V.G. Ferreira, D. Yang, S.A. Andam-Akorful, D. Yan, S. Osah, C.M. Hancock, G. Jing, A.T. Kabo-bah (2026). GeoidLab: An automated open-source Python toolbox for gravity-field analysis and vertical datum unification. Earth Science Informatics, vol. 19, 66. DOI: 10.1007/s12145-026-02118-6

download

tutorial