Changes between Version 4 and Version 5 of Processing/SRTMDEMs


Ignore:
Timestamp:
Jul 1, 2010 12:39:57 PM (9 years ago)
Author:
benj
Comment:

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  • Processing/SRTMDEMs

    v4 v5  
    33The Shuttle Radar Topography Mission mapped global elevations at a 3 arc second (90m posting) resolution between 60N and 56S. This is relatively coarse for DEM usage but is sufficient in some cases. To create a DEM from this data:
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    5 1. Obtain data from SRTM ([http://srtm.usgs.gov/ http://srtm.usgs.gov/]). This is most easily done via their [http://earthexplorer.usgs.gov Earth Explorer] - expand the "Digital Elevation" link on the left and tick the box labelled "SRTM". Enter bounding co-ordinates for the area you want data for, clicking the green "+" icon after each one. Note that this currently seems not to always work correctly for locations in DMS format (at least in Firefox), you may need to switch to decimal degrees (which work fine). Click on the "Search" button in the bottom-right, and you should be presented with a list of items matching your search (there should be only one thing in it). Click on the "SRTM" link (you may need to enable pop-ups if you've got them blocked), and you will be presented with a list of matching SRTM tiles and download links - download the data you want to use. Note that only SRTM 3-arc-second resolution data is available for sites outside North America.
     51. Obtain data from SRTM ([http://srtm.usgs.gov/ http://srtm.usgs.gov/]). This is most easily done via their [http://earthexplorer.usgs.gov Earth Explorer] - expand the "Digital Elevation" link on the left and tick the box labelled "SRTM". Enter bounding co-ordinates for the area you want data for, clicking the green "+" icon after each one. Note that this currently seems not to always work correctly for locations in DMS format (at least in Firefox), you may need to switch to decimal degrees (which work fine). Click on the "Search" button in the bottom-right, and you should be presented with a list of items matching your search (there should be only one thing in it). Click on the "SRTM" link (you may need to enable pop-ups if you've got them blocked), and you will be presented with a list of matching SRTM tiles and download links - download the data you want to use. Note that only SRTM 3-arc-second resolution data is available for sites outside North America. For sites in North America higher resolution data can be obtained via the USGS [http://seamless.usgs.gov/ Seamless Server]
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    772. Unzip the downloaded zip file and descend into the directory structure to find the file w001001.adf - this holds the actual data, though you can't move it without the rest of the directory structure.