Virginia’s Elevation Framework Layer Upcoming LiDAR Projects and the Elevation FIAT

1. Virginia’s Elevation Framework Layer Upcoming LiDAR Projects and the Elevation FIAT John Scrivani Geospatial Projects Manager VGIN Board Meeting April 7, 2010 www.vita.virginia.gov 1

2. Virginia Geographic Information Network Topics • Framework Layers & Spatial Data Infrastructure (SDI) • Elevation Data – NED and Elevation for the Nation • Virginia LiDAR Projects • Elevation Framework Initiative Action Team (Elevation FIAT)

3. Spatial Data Infrastructure Framework Layers (NSDI) Geodetic control Digital orthoimagery Elevation Transportation Hydrography Governmental Units Cadastral Presidential Executive Order 12906 April 1994 Virginia Geographic Information Network

4. Why “Infrastructure”? In the information age digitaldata is a basis for economic growth, public safety, public health, and environmental protection; Akin to asphalt roadways, metal pipes and public buildings.

5. Why “Framework”? • "themes of geospatial data that are used by most GIS applications“ OMB Circular A-16 Framework layers are: • Needed for many diverse purpose • Needed across all jurisdictions • Needed to be standardized and compatible • Too expensive to be created and used just once • Amenable to economies of scale

6. Elevation • distance measured upward along a plumb line between a point and the geoid (mean sea level) • a data layer representing the surface of the earth in a consistent fashion (datum, units, map projection) • Uses • Floodplain mapping, stream & watershed delineation • Engineering & construction • Real estate development • Pipeline and power line planning • Environmental analysis • Sources • Field surveys • Contour maps • Photogrammetric analysis of aerial photography • LiDAR

7. National Elevation Dataset • Coverage completed in 1997 • Seamless grid of • 30 meter (1 arc-seconds) • 10 meter (1/3 arc-seconds) • 3 meter (1/9 arc-seconds) • Overall vertical accuracy (RMSE) 2.44 m • Most areas in Virginia based upon 1960’s or older data

10. Elevation for the Nation A National Research Council committee in 2007 • Foundthat existing elevation data are too old and lack required accuracy • Proposed a national program called Elevation for the Nation to parallel the existing Imagery for the Nation concept • Recommended that LiDAR be the primary technology • Recommended that elevation data should be stored in the National Elevation Dataset (NED) • Recommended that the database should include both the original LiDAR point cloud and the edited bare-earth DEM

11. LiDAR (Light Detection and Ranging)

12. Multiple Returns

13. LiDAR Point Cloud Bare Earth DEM Digital Surface Model

15. LiDAR Projects 2010

16. Elevation Data Clearinghouses • Bare-earth DEM • NEDNational Elevation Dataset(USGS) • Point-cloud data • CLICKCenter for LiDAR Information Coordination and Knowledge (USGS)

17. Existing Contours from VBMP Orthos • 2002, 2006/07 and 2009 VBMP orthophoto flights produced digital terrain models • Primary purpose was orthorectification of the aerial images • Can be used as input for further photogrammetric analysis to create contours (4-ft from 1-ft imagery and 2-ft from ½-ft imagery) DTM – Digital Terrain Model

18. Elevation FIAT • The first Framework Initiative Action Team (FIAT) arising from VGIN’s recently adopted 2010-2015 strategic plan • Implements Initiative 5 –Provide framework data layers • FIAT Tasks: • Conduct an inventory of existing elevation datasets • Recommend elevation data standards and best practices • Promote coordination and collaboration on the development of new elevation datasets • Promote data sharing and incorporate elevation data in the existing clearinghouses

19. Thank You! Questions?