GHOST is a powerful software package for GPS based orbit determination of satellites low Earth orbit (LEO). GHOST comprises different modules for data preprocessing, kinematic positioning and reduced dynamic orbit determination using spaceborne GPS measurements. Satellite laser ranging data can, furthermore, be processed for orbit validaton purposes.
All programs build up on a common library of C++ modules for GNSS data processing, spacecraft trajectory modeling, and estimation. The GHOST library and application programs have been developed by DLR's German Space Operations Center (DLR/GSOC) in close cooperation with the Delft Institute of Earth Observation and Space Systems (DEOS) at TU Delft.
The GHOST suite is made up of individual tools that can freely be combined by the user to implement a mission specific processing scheme. All programs operate in a non-interactive mode which facilitates their use in script based procedures and the setup of automated processing chains.
Typically, the following steps are performed in sequence:
The entire processing chain requires some 5-10 min on a standard desktop computer for representative LEO data sets with 24-30h arcs, 10-30 s step size, and 8-12 receiver channels. Single-orbit arcs in a near-real-time orbit determination system can be processed within less than one minute.
GHOST employs state of the art dynamical and measurement models for the processing of GPS and SLR observations and the modeling of spacecraft trajectories.
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Montenbruck O., Gill E., Kroes R.;Rapid Orbit Determination of LEO Satellites using IGS Clock and Ephemeris Products;GPS Solutions 9, 226-235 (2005).DOI 10.1007/s10291-005-0131-0
Yoon Y.;Longterm Analysis of Precise Orbit Determination for the GRACE and CHAMP Missions;DLR-GSOC TN 07-02; Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen (2007).