The National Map
Data Delivery Updates
National Elevation Dataset (NED)
December 18, 2012: Changes with the delivery of NED 1- and 1/3-arc-second data
As part of the National Geospatial Program's plan for delivering data from a public Internet cloud provider by the end of 2013, The National Map is preparing pre-packaged, staged products for faster and more efficient downloads. As of December 18, 2012, National Elevation Dataset (NED) 1- and 1/3-arc-second data is available through pre-packaged, downloadable, 1- degree tiles in ArcGrid and GridFloat formats only. Users can still define custom areas of interest. However, all tiles intersecting the area of interest will be included in the delivery.
In addition, beginning with the April 2013 release of the NED, it is anticipated that all elevation products (1-, 1/3- and 1/9-arc-second DEMs) will be available as pre-packaged, downloadable files in '.img' format, a robust format easily read by nearly all GIS software. Due to 1/9 arc-second data's very large size, it will only be available as pre-packaged data in '.img' format through online download starting with the April NED release. And while USGS continues to offer ArcGrid and GridFloat formats through our bulk order process, all other format options for on-line download of 1/9 arc-second DEMS will no longer be available after the move to staged products is completed. To assist users in this transition to our new product format offerings, we are also providing downloadable file conversion scripts to assist users that need raster data in other formats. These scripts require either Esri ArcGIS or Geospatial Data Abstraction Library (GDAL) software for raster data file conversions.
For your convenience, we are also providing samples of pre-packaged NED data for you to download and test with the software you may be using. Each of these 'zipped' archives contain, along with the data, information and specifications specific to each dataset, as well as associated metadata. Please see the 'readme.txt' file which is included in each of the downloadable examples:
(Note: these are very large files.)
We are considering offering a second pre-packaged format for 1/9 arc-second data if budgets allow. We will be posting more information about the change to pre-packaged products soon. If you have questions or concerns about these changes, please contact us at firstname.lastname@example.org.