1 / 4

GTOPO30 Global 30-arc-second (1-km) elevation model

GTOPO30 Global 30-arc-second (1-km) elevation model. “ Best available” global DEM. Initial release: March 1997. Widely used for climate modeling, land cover characterization, hydrologic modeling, and EOS satellite image product generation.

khanh
Télécharger la présentation

GTOPO30 Global 30-arc-second (1-km) elevation model

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GTOPO30Global 30-arc-second (1-km) elevation model • “Best available” global DEM • Initial release: March 1997 • Widely used for climate modeling, land cover characterization, hydrologic modeling, and EOS satellite image product generation • Seamless raster data derived from multiple source datasets • GTOPO30 continues to be a very popular product, averaging over 12,000 files downloaded each month

  2. The National Elevation Dataset (NED) • Seamless national coverage of “best available” raster elevation data • Geographic “projection” • 1-arc-second (30-meter), 1/3-arc-second (10-meter), and 1/9-arc-second (3-meter) grid spacing • Alaska: 2-arc-second grid spacing • Datum: NAD 83 horizontal; NAVD 88 vertical • Elevation units: decimal meters • Updated bi-monthly to incorporate all new USGS DEM production and other newly available source data • NED is the elevation layer of The National Map

  3. Source Data Resolution 3 meters or better (3%) 10 meters or better (67%) 30 meters (30 %) National Elevation Dataset: Source Data April 2007 release: over 70% 10-meter DEM source or better

  4. Shuttle Radar Topography MissionData Distribution

More Related