Integer heights in the merged void-free DEM files are relative to the
EGM96 geoid (whereas the floating-point heights in the SRTM-only DEM files are relative to
the WGS84 ellipsoid).
num
0
255
Index indicating the data source and the number of source scenes.
0: Water in corrected SRTM water body data
1-23: SRTM 1-23 (max known is 23)
41-94: PRISM 1-50 (54 max polar, 37 max elsewhere)
110-160: GDEM3 (saturated at 50)
170-220: GDEM2 (saturated at 50)
231: SRTMv3 from GDEM3
232: SRTMv2 from GDEM3
233: SRTMv2 from GDEM2
234: SRTM-with-NGA-fill from GDEM2
241: NED from GDEM2 (USA)
242: NED from GDEM3 (USA)
243: CDED from GDEM2 (Canada)
244: CDED from GDEM3 (Canada)
245: Alaska from GDEM2 (Alaska)
246: Alaska from GDEM3 (Alaska)
250: Interpolation
251: Quad edge averaged where two neighboring quads disagreed (generally a GDEM error)
255: ERROR (if NUM IS MISSING - none known to exist)
swb
0
255
Updated SRTM water body data
0: Land
255: Water
* estimated min or max value
swb Class Table
Value
Color
Description
0
brown
Land
255
cadetblue
Water
Terms of Use
Terms of Use
Unless otherwise noted, all NASA-produced data may be used for any purpose without
prior permission. For more information and exceptions visit the
NASA Data & Information Policy page.
NASADEM is a reprocessing of SRTM data, with improved accuracy by incorporating auxiliary data from ASTER GDEM, ICESat GLAS, and PRISM datasets. The most significant processing improvements involve void reduction through improved phase unwrapping and using ICESat GLAS data for control. Documentation: User's Guide
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],[],[[["NASADEM is a NASA product providing a global Digital Elevation Model (DEM) at 30-meter resolution."],["It is derived from SRTM data and enhanced with ASTER GDEM, ICESat GLAS, and PRISM datasets for improved accuracy and void reduction."],["The dataset includes elevation, data source index, and updated water body data bands."],["NASADEM data is freely available for use with proper attribution to NASA JPL."],["Earth Engine users can access and analyze NASADEM data using the provided code snippet."]]],["The NASADEM dataset, provided by NASA/USGS/JPL-Caltech, offers reprocessed SRTM elevation data from February 11-22, 2000, with 30-meter pixel resolution. It includes `elevation`, `num` (data source index), and `swb` (water body) bands. NASADEM enhances SRTM by integrating data from ASTER GDEM, ICESat GLAS, and PRISM to reduce data voids and improve accuracy. Data is freely available for any purpose and can be accessed via an Earth Engine snippet and linked JavaScript code.\n"]]