Related Research Areas
Earth Surface & Interior

Geodetic control is extremely important in the production and quality control of topographic data sets, enabling elevation results referenced to an absolute vertical datum. In the last decade NASA executed two spaceflight missions, the Shuttle Radar Topography Mission (SRTM) and the Ice, Cloud and land Elevation Satellite (ICESat) which provide global topographic data sets with quantified measurement errors. SRTM interferometric synthetic aperture radar (InSAR) data were acquired in February 2000 between ~60°N and ~57°S. The SRTM 90-m digital elevation models (DEMs) now serve as the global topography reference surface used in natural hazard, land cover and climate change studies. However, meter-scale long-wavelength elevation biases remain in the data, imposing errors in resulting products and scientific results. A complementary data set is the globally distributed laser altimetry profiles (± 86°) from ICESat; data acquisition began in February 2003 and is ongoing. We propose to select ICESat data yielding land-surface elevations with decimeter accuracy to build a global, geodetic, ground control point (GCP) database that will be used to assess and correct spatially varying elevation biases in the SRTM topographic data. The proposed work will directly contribute to an effort led by Collaborator Mike Kobrick entitled “The Definitive Merged Global Digital Topographic Data Set” focused on improving the SRTM topographic data products. The ICESat GCP database can also be used to provide control for the production of future topographic data, such as that from stereo-photogrammetric images acquired by ASTER onboard NASA’s Terra platform and from ESA’s TanDEM-X InSAR mission. Global topographic data with improved geodetic accuracy achieved using the global GCP database will enable more accurate characterization of coastal inundation hazards and land surface changes related to solid Earth processes, natural hazards and climate change.

Project PI: Claudia Carabajal/Sigma Space Corporation

NASA/GSFC Mail Code 698 Greenbelt, MD 20771

Phone: 301.614.6111

Fax: 301.614.6099



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Started: Aug 09, 2010

Last Activity: Dec 10, 2010


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