How can I get updates for the NED 1 arc second data and NED 1/3 arc second?
A. A visual index is at Data Source Index map showing the areas that have been updated and when for both the NED 1 arc second and NED 1/3 arc second. Metadata and shapefiles of updates can be found at ftp://edcftp.cr.usgs.gov/pub/data/ned For NED 1 arc second, a standing request can be setup within Earth Explorer, http://earthexplorer.usgs.gov to receive notifications of updates. You would have to be a registered user to enable this service. You can order them through earthexplorer or customer service. For NED 1/3 arc second, the best way is to download the metadata and shapefiles for the NED 1/3 arc second from ftp://edcftp.cr.usgs.gov/pub/data/ned Then compare dates with what was received and what may have been updated.
