3.1 Installation of a Permanent GPS Station at the Pyramid International Laboratory-Observatory, Nepal
Dipartimento di Scienze Matematiche, Università degli Studi di Trieste
Principal Investigator: Prof. Giorgio Poretti
Objectives
The proposed research provided the installation of a permanent GPS station at the Everest Pyramid Laboratory with the purpose of establishing a link with the GPS station already installed in Lhasa (Tibet) by research Institutions of China and Germany in the field of Geodesy. This station will also be linked with other GPS stations installed in Nepal by United States researchers. Being linked to the DORIS orbitography station it will provide information on long range and short range tectonic movements. AM broadcasting of RTCM corrections would allow to locate the points of the area with meter accuracy necessary for exploration, alpine rescue and GIS.
Description of the project
After the geodetic campaigns of 1991 and 1992 and with the installation of the DORIS orbitography station, the Pyramid Laboratory has become a reference point for Himalayan geodesy. Several requests were made during the last decade of recording at the GPS point near the Pyramid in occasion of international GPS campaigns from researchers of several countries as Germany, China, France and the United States.
Since 1995 the Chinese NBSM (National Bureau of Surveying and Mapping) is running a permanent GPS station in Lhasa.
New research programmes can greatly benefit from the availability of the data of a permanent station and from receiving RTCM corrections for DGPS locations.
Materials and methods
The GPS station is located on the hill near the Pyramid on the point named with the letter G during the 1992 campaign. A GPS antenna installed there will be linked to a computer in the Pyramid Laboratory. The antenna is on a pole properly insulated and higher than the possible snow level in winter.
It operates at a rate of 30 sec. The computer will be programmed to retrieve data through Internet satellite connection.
Results of the first year
In 2002 two Leica 530 GPS stations and the transmitting system to the Pyramid Laboratory were purchased. This first temporary installation allowed to obtain sufficient data to judge the goodness of the site that was chosen in 1991, linked to the Doris system antenna at the Pyramid and used as a reference point for several surveys during the last 10 years.
From the analysis of the recorded data it has been decided, as final destination, to put the permanent station on a nearby point, with better view of the sky, and link it to the present point with a suitable session of measurements during the month of October 2003.
Results of 2nd and 3rd year
Between 2003 and 2004 the GPS station recorded for more than 6 months. The analysis of the data allowed an interesting comparison with those recorded in 1991-1992 and with the results from the DORIS System.
Some unexpected gaps in the recordings suggested accurate investigations on the hardware. The system was then carried back to Italy in September 2004 for a technical check.
At the moment the reason seem to be in a faulty memory card but the checks are proceeding on other components.
In April 2004 the system will be installed again. In this occasion the data will be made available through Internet after a validation processing.
Results of the processing of the 2003-2004 data were presented at the CNR Workshop in Rome on the 17th of December 2004. They will be published in the proceedings. The English version, recently completed will also be published soon.
Programme for 2005
After the check-up of the system in Italy, the system will be sent back to the Pyramid Lab for a new installation.
As previously planned the data will be preprocessed and make available in Internet after a new session of analysis on the recorded data.