Data Quality and Coordinate Monitoring for a Permanent Network: Proposals and Experiences

L. Biagi, S. Caldera, and M.G. Visconti

Abstract:	A positioning service based on a GNSS network of permanent stations materializes the global reference frame and distributes it to its users, by distributing the estimated coordinates of the permanent stations, their raw data and other network products. In these years, positioning services are under development in Italy; typically they are designed, created and managed at the spatial scale of the Italian Regions. The first of them, located in Lombardia Region, has been designed and implemented starting from 2003: from January 2006 it is distributing data and products for real time and post processing applications. Three data quality checks and coordinate monitoring processes are performed, at three different latency levels. The first check is directly managed by the software that acquires RTCM streams from the stations to compute the real time network products. The final monitoring is made at a completely different latency and is finalized to the estimation of the permanent stations coordinates; it is computed by the daily adjustment of the Lombardia network within the IGS network, by constraining IGS stations to their published coordinates and by using the final IGS products; the final adjustment is computed with a two weeks latency: the solutions are analyzed and stored to check discontinuities and infer trends in the coordinates; moreover suitable quality indexes are extracted from the adjustment outputs in order to check the data quality: the exceeding of assigned thresholds by the indexes is automatically signalized. A further adjustment is performed to check both the data quality and the coordinates stability in near real time. It runs daily, immediately after midnight, by using ultra rapid IGS ephemerides and only Lombardia stations: also in this case the data quality is checked by analyzing the elaboration outputs; the coordinates stability is checked by comparing the results with the coordinates estimated in the final monitoring. The final monitoring is operating from January 2006, while the near real time quality has started in the last months. At first, the paper describes the Lombardia positioning service implementation; then, the choices adopted, the procedures implemented and the results obtained in one year of monitoring are discussed; at last the near real time quality check is described.
Published in:	Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007) September 25 - 28, 2007 Fort Worth Convention Center Fort Worth, TX
Pages:	687 - 698
Cite this article:	Biagi, L., Caldera, S., Visconti, M.G., "Data Quality and Coordinate Monitoring for a Permanent Network: Proposals and Experiences," Proceedings of the 20th International Technical Meeting of the Satellite Division of The Institute of Navigation (ION GNSS 2007), Fort Worth, TX, September 2007, pp. 687-698.
Full Paper:	ION Members/Non-Members: 1 Download Credit Sign In