Design of a web-based GNSS data management system at HartRAO: preliminary results

The Space Geodesy Programme of the Hartebeesthoek Radio Astronomy Observatory (HartRAO) is actively engaged in improving the African Earth and Ocean Monitoring Network (sub-project 1.1 of Inkaba yeAfrica) by installing geodetic, oceanographic and geophysics stations across the Sub-Saharan region and Southern ocean. This forms part of the drive to monitor different geophysical parameters via denser networks and with increasing accuracies, so as to better our understanding of the Earth system. The instruments being deployed include Global Navigation Satellite Systems (GNSS) stations, tide-gauges, seismic stations and meteorological units. There are four main space geodetic techniques collocated at HartRAO, making it a fiducial site in Africa. These techniques are GNSS, Satellite Laser Ranging (SLR), Very Long Baseline Interferometry (VLBI) and Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS). It is important to ensure that all the collected raw scientific data as well as the derived data products are accessible in a user-friendly manner. Additionally, a new data management system needs to be implemented at HartRAO in order to ensure data integrity. This paper focuses on the implementation of a GNSS data management system. The automated system for the pre-processing and post-processing of GNSS data and other derived products are presented. The data products are then visualized utilizing an interactive web-based map. These scientific products are important in understanding processes that occur on planet Earth such as plate motion, crustal deformation and weather patterns. The implementation of this data management system will facilitate the monitoring of these processes.