High Resolution 1:10,000 scale Mapping Strategy of Multi ... - NDMA

1. Elevation for the Nation should employ LIDAR as the primary technology for
digital elevation data acquisition. LIDAR is capable of producing a bare-earth
elevation model with better than 0.5 m equivalent contour accuracy in most
terrain and land cover types; a 1.0 m equivalent contour accuracy is more
cost-effective in mountainous terrain, and a 1-foot equivalent contour
accuracy can be achieved in very flat coastal or inland floodplains. A
seamless nationwide elevation database created at these accuracies would
meet requirements for floodplain mapping for the nation.
2. A seamless nationwide elevation model has application beyond the Map
Modernization program; some local and state governments are acquiring
LIDAR data at these accuracies or better.
3. The new data collected in Elevation for the Nation should be collated with
existing data set as part of an updated National Elevation Dataset
4. The Elevation for the Nation database should contain the original LIDAR mass
points and edited bare-earth surface, as well as any break lines required to
define essential linear features.
5. In addition to the elements proposed for the national database, secondary
products including triangulated irregular networks, hydrologically corrected
digital elevation models, and hydrologically corrected stream networks and
shorelines should be created to support floodplain mapping. Standards and
interchange formats for these secondary products do not currently exist and
should be developed. Comprehensive standards for LIDAR data collection
and processing are also needed.
6. DEM/DSM/DTM model to be created for catchment areas in 1: 2,000 scale
where contour intervals better than 0.5 meter
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