HR: 1340h
AN: G33A-0032    [Abstracts]
TI: Effect of Using the High Resolution SRTM Digital Elevation Model on the Determination of a Precise Geoid Model: A Case Study in Iran
AU: * Kiamehr, R
EM: ramin@infra.kth.se
AB: Any errors in digital elevation models (DEMs) will introduce errors directly in gravity anomalies and geoid models, via their use in interpolating Bouguer gravity anomalies. Errors are also propagated into the geoid model by the topographic and downward continuation corrections in the application of StokesA›ƒ,ªƒ,›s formula. The effects of these errors are assessed by the evaluation of the absolute accuracy of nine independent DEMs for the Iran region. It is shown that the improvement in using the high-resolution Shuttle Radar Topography Mission (SRTM) data versus previously available DEMs in gridding of gravity anomalies, terrain correction and downward continuation effect for the geoid model are significant. We found very large differences between the GLOBE and SRTM models on the range of -750 to 550 m. This difference causes an error in the range of -160 to 140 mGal in interpolating surface gravity anomalies and -60 to 60 mGal in simple Bouguer anomaly correction terms. In the view of geoid heights, we found large differences between GLOBE and SRTM models, in the range of -1.1 to 1 m for the study area. The terrain correction of the geoid model in selected GPS/levelling points differs only within 3 cm for these two DEMs.
DE: 1200 GEODESY AND GRAVITY
DE: 1214 Geopotential theory and determination (0903)
DE: 1219 Gravity anomalies and Earth structure (0920, 7205, 7240)
DE: 1240 Satellite geodesy: results (6929, 7215, 7230, 7240)
DE: 1241 Satellite geodesy: technical issues (6994, 7969)
SC: Geodesy [G]
MN: Fall Meeting 2005