Discussion Forums : 3DEP Steering Group
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 Subject : USGS 3DEP Lidar Indexing for Continental US.. 11/13/2017 04:32:30 PM 
Molly Schar
Posts: 84
Location: New Orleans, LA
(From 11/13/17 GeoJava)

Last month, the USGS released a 2 page fact sheet outlining their plans to align their 3DEP Lidar program with a standardized national grid. The proposed grid would guide the shape of proposed 3DEP grant projects (optional for 2018 but required in 2019) and, presumably, the distribution files for 3DEP data.

This new component of the 3DEP program has been encouraged by NSGIC members in recent years. The grid may prove useful as a framework for negotiating coverage and costs between adjacent project/interest areas. It is also likely the grid will help USGS facilitate 'infill' between larger gaps found between proposed projects and/or existing data.

Also of note, the US National Grid system, based on the military reference system, was given consideration but in the end was not selected. The logic seems solid on this for the reasons USGS cites, although it does mean that most projects will no longer have a true North-South orientation. (Chalk this up in the 'if no one's perfectly satisfied, you might have a good solution' category).

With that said, side bets are being taken by most online betting sites as to where the, as yet unveiled, origin of the Albers (EPSG:6350) equal area-based grid will be located. Current odds are as follows:
  • 5:4 - "On the Thousands" (mod {X,Y}(1000) = 0).
  • 4:1 - Main flagpole at 12201 Sunrise Valley Dr, Reston Virginia
  • 7:1 - 39.053535, -77.346434
  • 9:1 - #2 15th St NW, Washington, DC
Molly Schar, Executive Director
National States Geographic Information Council
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