11 datasets

NASA Earthdata CMR2023 · Array · NetCDF

This data product contains monthly ice sheet elevation change data for Antarctica derived from five radar altimetry missions (Geosat, ERS-1 and -2, Envisat and CryoSat-2) and two laser altimetry missions (ICESat and ICESat-2). Each time step and grid node includes relative error estimates and a quality flag that can be used to filter the data in space and time. The product is also provided with an

NASA Earthdata CMR + NASA Data Portal2001 · Raster · GeoTIFF

A Digital Elevation Model (DEM), ice thickness grid, and bedrock elevation grid of Greenland, acquired as part of the PARCA program. DEM data are a combination of ERS-1 and Geosat satellite radar altimetry data, Airborne Topographic Mapper (ATM) data, and photogrammetric digital height data. Ice thickness data are based on approximately 700,000 data points collected in the 1990s from a University

NASA Earthdata CMR + NASA Data Portal2001 · Astronomical catalogue

Southern Greenland ice sheet elevation change estimates are derived from SEASAT and GEOSAT radar altimetry data from 1978 to 1988. Data are confined to 61-72 deg N, 30-50 deg W, above 1700 m elevation. The addition of GEOSAT Geodetic Mission (GM) data results in twice as many crossover points and 50% greater coverage than previous studies. Coverage above 2000 m elevation is improved to 90%, and ab

NASA Earthdata CMR + NASA Data Portal1999 · Astronomical catalogue

The Antarctic atlas consists of 28 digital elevation maps which cover all of Antarctica north of 72.1 degrees south at a resolution of three kilometers. Each map contains surface elevations and coordinates for one atlas page covering 16 degrees of longitude. Data were acquired by the Geodetic Satellite (GEOSAT) Geodetic Mission (GM) from March 1985 through September 1986 and are available in both

NASA Earthdata CMR + NASA Data Portal1997 · Astronomical catalogue

The Digital SAR Mosaic and Elevation Map of the Greenland Ice Sheet combines the most detailed synthetic aperture radar (SAR) image mosaic available with the best current digital elevation model. The mosaic image shows both the location of the ice edge and the distribution of melt-related 'scatterers' on the surface. These scatterers include ice lenses and complex layered structure in the percolat

NASA Earthdata CMR + NASA Data Portal1997 · Astronomical catalogue

Note: This data set is now on HTTPS, so references to CD-ROM are historic and no longer applicable. The Ice Altimetry System (IAS) data set contains surface elevations of the Antarctic and Greenland ice sheets derived from Seasat and GEOSAT radar altimetry data. The Seasat data were collected for a continuous 90 days in 1978, at latitudes between 72 degrees South and 72 degrees North. GEOSAT was l

NASA Earthdata CMRcollection

GRAVSAT provides gravity survey information for the offshore oil and gas exploration industry. Based on the analysis of radar altimetry from the ERS-1 Geodetic Phase, completed in March 1995, high resolution gravity information is derived from the along track sea surface slopes measured by the satellite. At the equator, tracks are approximately 8km apart, reducing to 4km at 60 degrees of latitude,

NASA Earthdata CMRcollection

Gravity models are powerful tools for mapping tectonic structures, especially in the deep ocean basins where the topography remains unmapped by ships or is buried by thick sediment. We combined new radar altimeter measurements from satellites CryoSat-2 and Jason-1 with existing data to construct a global marine gravity model that is two times more accurate than previous models. We found an extinct

NASA Earthdata CMRcollection

This collection contains Sensor Data Records (SDRs), Geodetic Data Records (GDRs), Waveform Data Records (WDRs), and Crossover Difference data Records (XDRs) from the GEOSAT Geodetic Mission (GM) and Exact Repeat Mission (ERM) for the time period of March 30, 1985 to December 31, 1989. Parameters include: time, orbit, latitude/longitude, and sea surface height. Corrections to the data include: sea

NASA Earthdata CMRcollection

The sea surface topography (SSTop) spherical harmonic model, being complete through degree and order 10, has a spatial half wavelength resolution of 2000 km. It is derived in a joint orbit/gravity/SSTop solution (GRIM4-C3T) exploiting GEOSAT (doppler- and) altimeter data of observation period 1986, Dec. 14-31. The overall standard deviation is estimated to be about 15 cm. Satellite tracking data o

NASA Earthdata CMRcollection

GRIM4-C global gravity field models are based on the analysis of satellite orbit perturbations, evaluating optical, doppler and laser tracking data of about 30 satellites, combined with 1degx1deg gravity anomaly data sets completed by geoid undulations over the oceans derived from satellites altimetry or by directly evaluating altimeter data. The models are given as a set of fully normalized spher