This data set produces GPS raw data called RINEX (Receiver INdependent EXchange format) files, containing clock information for microwave propagation between GPS satellites and an antenna. The GPS antenna has been in Siberut, Mentawai Islands, west Sumatera, Indonesia since September 2002 (now in progress). Time interval of the raw data is 30-second. This site has been operated in JAMSTEC/IORGC research project.
In order to estimate precipitable water vapor from the GPS raw data, it's necessary to calculate atmospheric delay by using GPS analysis software, and then translate the atmospheric delay to precipitable water vapor by using surface pressure and temperature, which have been measured together with GPS data at the same site (see the description for AWS in Siberut). Time interval and estimated value of the atmospheric delay depend on parameter settings of the analysis software. Now the JAMSTEC/IORGC research project has GIPSY-OASIS and Bernese software licences.
1) Data format
ASCII text files (RINEX files)
2) Spatial coverage & resolution
Longitude:99.2E, Latitude:1.58S, Elevation:12m a.s.l.
The GPS antenna receives microwave signals from all satellites above the horizon (actually low elevation angle signals are excluded in the calculation process because of high noise). Therefore, the GPS data represents approximately 20km horizontal scales.
3) Temporal covergage & resolution
since September 2002, every 30-second
4) File size (total)
approx. 2MB/day, 700MB/year
References & related publication
- Wu, P., J.-I. Hamada, S. Mori, Y.I. Tauhid, M.D. Yamanaka, and F. Kimura, Diurnal variation of precipitable water over a mountainous area of Sumatra Island. J. Appl. Meteorol., 42, 1107-1115, 2003.