Evaluation of vertical accuracy of open source Digital Elevation Model (DEM)

Near-global validation of the SRTM DEM using satellite radar altimetry

This text is an updated English translation of Satellitengeodasie, a book that was published in German in 1989. The text is the first in many years that attempts to cover the broad spectrum of methods, applications, and systems, both classical and current, that have developed in the field of satellite geodesy.

The material is presented in a structure that follows the major observational methods used in satellite geodesy: classical techniques, Doppler, GPS, laser, altimetry, and special methods including satellite-to-satellite tracking, satellite radiometry, and VLBI. Before introducing these observational techniques in detail, the author provides the fundamentals on reference frames, time signal propagation, orbital mechanics and basic applications of satellite geodesy in positioning, gravity field modeling, navigation, marine geodesy, kinematics, and geodynamics. An excellent reference list completes the text.

Satellite Geodesy—Foundations, Methods, and Applications

The Shuttle Radar Topography Mission (SRTM) provides for the first time a near-global high-resolution digital elevation model (DEM) with great advantages of homogeneous quality and free availability. The last 10 years or so have seen rapid advances in the data processing and applications of SRTM DEM. From the perspective of SRTM, we present in this article a brief overview of the principles, datasets, void filling and accuracy of SRTM DEM first. Special emphasis is on its application advances in various research fields including, but not limited to, geology, geomorphology, water resources and hydrology, glaciology, evaluation of natural hazards and vegetation surveys. Problems that arose from the applications and the future research interests are also addressed. We hope this study will greatly facilitate the ease of use of SRTM DEM in extensive fields.

SRTM DEM and its application advances

A GIS-based seismic hazard, building vulnerability and human loss assessment for the earthquake scenario in Tabriz

Iran is one of the most complicated areas in the world from the view of rough topography, tectonic activity, large lateral density and geoidal height variations. The computation of a regional gravi ...

/pdf/precise-gravimetric-geoid-model-for-iran-based-on-grace-and-1me8ixd7xv.pdf

Precise Gravimetric Geoid Model for Iran Based on GRACE and SRTM Data and the Least-Squares Modification of Stokes’ Formula : with Some Geodynamic Interpretations

Any errors in digital elevation models (DEMs) will introduce errors directly in gravity anomalies and geoid models when used in interpolating Bouguer gravity anomalies. Errors are also propagated into the geoid model by the topographic and downward continuation (DWC) corrections in the application of Stokes’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 corrections and DWC effects for the geoid model are significant. Based on the Iranian GPS/levelling network data, we estimate the absolute vertical accuracy of the SRTM in Iran to be 6.5 m, which is much better than the estimated global accuracy of the SRTM (say 16 m). Hence, this DEM has a comparable accuracy to a current photogrammetric high-resolution DEM of Iran under development. We also 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 the use of GLOBE and SRTM DEMs, in the range of −1.1 to 1 m for the study area. The terrain correction of the geoid model at selected GPS/levelling points only differs by 3 cm for these two DEMs.

Effect of the SRTM global DEM on the determination of a high-resolution geoid model: a case study in Iran

The least squares modification of Stokes formula has been developed in a series of papers published in Journal of Geodesy between 1984 and 2008. It consists of a least squares (stochastic) Stokes k ...

The new gravimetric quasigeoid model KTH08 over Sweden

A number of regional gravimetric geoid models have recently been determined for the Iran area, and a common problem is to select the best model, e.g. for engineering applications. A related probl ...

Comparison of the qualities of recent global and local gravimetric geoid models in Iran

The computation of regional gravimetric geoid models with reasonable accuracy, in developing countries, with sparse data is a difficult task that needs great care. Here we investigate the procedu ...

A strategy for determining the regional geoid by combining limited ground data with satellite-based global geopotential and topographical models: a case study of Iran

Ramin Kiamehr

Papers

Precise Gravimetric Geoid Model for Iran Based on GRACE and SRTM Data and the Least-Squares Modification of Stokes’ Formula : with Some Geodynamic Interpretations

Effect of the SRTM global DEM on the determination of a high-resolution geoid model: a case study in Iran

The new gravimetric quasigeoid model KTH08 over Sweden

Comparison of the qualities of recent global and local gravimetric geoid models in Iran

A strategy for determining the regional geoid by combining limited ground data with satellite-based global geopotential and topographical models: a case study of Iran