HR: 09:15h
AN: G51D-06    [Abstracts]
TI: Ray-traced tropospheric total slant delays for GNSS processing
AU: * Hobiger, T
EM: hobiger@nict.go.jp
AF: Space-Time Standards Group, National Institute of Information and Communications Technology (NICT), Japan, 893-1 Hirai, Kashima, 314-0012, Japan
AU: Ichikawa, R
EM: richi@nict.go.jp
AF: Space-Time Standards Group, National Institute of Information and Communications Technology (NICT), Japan, 893-1 Hirai, Kashima, 314-0012, Japan
AU: Hatanaka, Y
EM: hata@gsi.go.jp
AF: Geographical Survey Institute, Japan, 1 Kitasato, Tsukuba, 305-0811, Japan
AU: Yutsudo, T
EM: hobiger@nict.go.jp
AF: Geographical Survey Institute, Japan, 1 Kitasato, Tsukuba, 305-0811, Japan
AU: Iwashita, C
EM: hobiger@nict.go.jp
AF: Geographical Survey Institute, Japan, 1 Kitasato, Tsukuba, 305-0811, Japan
AU: Miyahara, B
EM: basara@gsi.go.jp
AF: Geographical Survey Institute, Japan, 1 Kitasato, Tsukuba, 305-0811, Japan
AU: Koyama, Y
EM: koyama@nict.go.jp
AF: Space-Time Standards Group, National Institute of Information and Communications Technology (NICT), Japan, 893-1 Hirai, Kashima, 314-0012, Japan
AU: Kondo, T
EM: kondo@nict.go.jp
AF: Space-Time Standards Group, National Institute of Information and Communications Technology (NICT), Japan, 893-1 Hirai, Kashima, 314-0012, Japan
AB: Numerical weather models have undergone an improvement of spatial and temporal resolution in the recent years, which made their use for GNSS applications feasible. Ray-tracing through such models permits the computation of total troposphere delays and ray-bending angles. At the National Institute of Information and Communications Technology (NICT), Japan the so-called KAshima RAy-tracing Tools (KARAT) have been developed which allow to obtain troposphere delay corrections in real-time. Together with fine-mesh weather models from the Japanese Meteorological Agency (JMA) huge parts of the East Asian region, including Japan, Korea, Taiwan and East China, can be covered. The Japanese GEONET with its more than 1300 GNSS receivers represent an ideal test-bed for the evaluation of the performance of KARAT. In cooperation with the Geographical Survey Institute (GSI), Japan more than 1.6 billion observations, covering measurements from July 1st until August 31st, 2006, were processed and the corresponding troposphere delays were used to modify the original RINEX files by subtraction of code- and phase delays. These modified observations were processed by a dedicated analysis run of the GEONET operation center, taking advantage of the computer cluster at GSI. First results from this study, together with an in-depth discussion about the assets and drawbacks of the reduction of troposphere total slant delays will be given in this presentation. Additionally an overview about KARAT, the treatment of observational data and the impact of future refined numerical weather models on GNSS analysis will be included in this contribution.
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1243 Space geodetic surveys
DE: 1294 Instruments and techniques
SC: Geodesy [G]
MN: 2007 Fall Meeting