Since the early 1990s, the GFZ has operated a global GNSS station network with currently about 30 stations for research purposes, such as precise satellite clock & orbit determination, radio occultation measurements or studies on crust dynamics (see figure 1).
These stations, which are operated all over the world, are kept on a modern hardware level in order to adapt to the innovations of satellite geodesy and to make the data available to the research activities. On the software side, it is important to keep up with the hardware changes and to ensure a reliable station operation. The software is in the house so that a quick adaptation to extraordinary requirements of scientific projects is possible. The majority of the stations are integrated into international collaborations and provide data for the IGS-MGEX and the CONGO network. The data from some selected stations also contribute to the ESA mission GRAS / MetOp.
These are currently equipped with 'JAVAD TRE_G3TH DELTA' receivers and 'JAV_RINGANT_G3T' choke ring antennas and allow the data recording of GPS (L1 / L2 / L5), GLONASS (L1 / L2) and Galileo (L1 / L5) signals. The antennas were individually calibrated in the calibration chamber of the University of Bonn (Germany). The stations provide real-time measurements in JAVAD proprietary format as well as RTCM-3. They are stored in the Rinex-2 and Rinex-3 format for post-processing of the observation data and can also be obtained from the GFZ, if required. Since the reception of the Chinese Beidou system is only possible to a limited extent, a further upgrade of the stations is aimed at.
In addition to the global stations, cross-section GNSS campaigns, e.g. in Indonesia. For this purpose, a compact, energy-saving registration system (tinyPC / 3) was developed and successfully implemented under extreme conditions e.g., the Dead Sea or the Antarctic).
Uhlemann, M.; Ramatschi, M.; Gendt, G. (2012): GFZ's Global Multi-GNSS Network and First Data Processing Results. IGS Workshop (Olsztyn, Poland 2012).