GRGS > Research > Software

Bureau des longitudes Centre national d’études spatiales Institut national de l'information géographique et forestière - Laboratoire LAREG Observatoire de Paris Institut national des sciences de l'Univers Observatoire de la Côte d'Azur Service Hydrographique et Océanographique de la Marine Observatoire Midi-Pyrénées Université de la Polynésie Française Ecole Supérieure des Géomètres et Topographes - Conservatoire national des arts et métiers Ecole et Observatoire des Sciences de la Terre

GINS software (Geodesy by Simultaneous Digital Integration) is developed and maintained by the Space Geodesy team at CNES for its research activities within the framework of the Space Geodesy Research Group (GRGS). It is an application for precise orbit determination applied to space geodesy that enables us to determine many physical or geodetic parameters through observations from space.These parameters are of three types:

1. geometric (such as station positions and the geocenter, parameters of the rotation of the Earth or other planets...),
2. dynamic (such as the coefficients for spherical harmonics of the gravity field or the tides, the coefficients of surface forces, the parameters of the thermosphere, the thermo-optical characteristics of a satellite...),
3. measurement (such as tropospheric delay corrections, timing, frequency...).

This software includes a process of digital integration of differential equations of satellite motion or of a constellation of satellites in an inertial reference frame, taking into account all gravitational and surface forces acting on the satellite as well as the motion of the specified attitude of the satellite according to its macro model.

It also allows for the adjustment, using the method of least squares, of the ephemerides produced as well as other parameters using geodetic tracking data of the GPS type (either a GNSS constellation or measurements between the satellites of a constellation and satellites in low orbit), or Doppler (ex., DORIS), laser, optical, altimetric ... Moreover, it can process VLBI and Lunar Laser types of data.


In addition, this software can be used in mission analysis given that most of the measurements described can be simulated to test new features or new satellite missions.

GINS is also a tool for planetary geodesy that enables us to calculate the trajectory of an artificial satellite around any body of the solar system: a planet, a natural satellite, a small body or the Sun.

GINS includes a series of dependent software, such as PREPARS, that gathers and prepares useful information for processing, or the DYNAMO modules for managing and solving normal equations, and related programs such as OV for the comparing orbits or GINO for the graphical display of results.

This software is available for PCs with Internet access to the database environmental files, for research teams, subject to the acceptance of the User Agreement (contact:


Algorithmic Documentation of the GINS Software, GRGS Report, December 2013

The CATREF software (Combination and Analyses of Terrestrial Reference Frame) is used for computing the realizations of the International Terrestrial Reference System. It allows for a rigorous combination of terrestrial reference frames. Its development and maintenance are assured by the IGN / LAREG team.

MATLO (Mathematics for Positioning and Orbitography), used by the GRGS analysis center of the ILRS, and jointly developed by the Observatoire de la Cote d'Azur and IGN / LAREG, can be used to estimate the terrestrial reference frame, the Earth orientation parameters, and range biases for from Satellite Laser Ranging observations. It also estimates simultaneously orbital parameters using a semi-dynamic method.