LiDAR-Based Elevation & Accuracy for Data in LiDAR-Based Elevation Maps Folder
For maps shown in the LiDAR-Based Elevation Maps folder, LiDAR-based elevation rasters were acquired for free from OGRIP (2012). Elevation data based on LiDAR for areas in the United States can be acquired for free from the USGS Naional Map (which can be accessed in the Data Sources in the Free section). LiDAR-based elevation is a 1/9 arc-second (about 3-meter resolution) National Map product.
LiDAR 1-meter DEM accuracy from Haneberg (2008; pdf)
• Haneberg (2008) reported that 1-meter resolution LiDAR DEMs (based on 1.5 m pulse spacing with overlap that produced about 1 pulse/m² and inverse distance squared interpolation to produce a 1-meter DEM raster) had an elevation error range from –4.88 m to +3.32 m (meters) with an average error of –0.11 m, and a standard deviation of 0.75 m.
• Always check the metadata for accuracy information that may be listed.
LiDAR elevation data for Ohio from OGRIP represent bare earth surfaces in 2006 or 2007. The data was acquired for the state of Ohio at an average post spacing of about 2 meters, then a 2.5 foot raster was derived as a product for download (data can also be acquired in .las or ASCII .txt file formats). In the process of converting the original Ohio LiDAR (.las) elevation points to a rasters, correction and smoothing of the data both occurred to improve the data.
Reference
Haneberg, W.C. 2008. Elevation errors in a LiDAR digital elevation model of West Seattle and their effects on slope stability calculations, in R.L. Baum, J. Godt, and L. Highland, editors, Landslides and Engineering Geology of the Greater Seattle Area, Washington: Geological Society of America Reviews in Engineering Geology 20, p. 55-65 (doi: 10.1130/2008.4020[03]).
OGRIP. 2012. Ohio Geographically Referenced Information Program. Cited at: http://ogrip.oit.ohio.gov/. Last updated: 2012.