Elevation | LiDAR
A coordinated effort with the federal USGS 3D Elevation Program (3DEP) Program
Download LiDAR (compressed .las files) or Download DEMs (Digital Elevation Models)
The Department of Finance and Administration, STS-GIS Services has been awarded three USGS grants ($670,000 in 2014, $600,000 in 2015, and $501,725 in 2016) to support geospatial data development in Tennessee. Through the US Geological Survey (USGS) and their 3D Elevation Program (3DEP), LiDAR (Light Detection and Ranging) data was collected for 27 counties along the Cumberland Plateau in December 2015 – January 2016, 18 counties were collected for East TN (along with Davidson County) from January thru March in 2016, and an additional 11 counties will be collected in late winter/early spring 2017. Additional funding to support these projects are coming from the Tennessee Department of Transportation, Tennessee Department of Environment and Conservation, the Tennessee Valley Authority, Department of Energy, Department of Agriculture and F&A, STS-GIS Services along with several other local governments in Tennessee. Plans are to complete statewide acquisition in 2018 with additional funding from the USGS 3DEP program.
The following sections provide detailed information about the project's Business Plan/Tech Specs, a LiDAR FAQ sheet, a LiDAR Inventory Map, Business Plan Events and a LiDAR Resources page.
The first step to accomplish our mission on this project is to create a business plan that identifies the business requirements, costs, and benefits of creating a LiDAR derived elevation GIS dataset. In addition, documenting the appropriate technical specifications, and related processes to the LiDAR data, is a foundational element associated with this project.
Using grant funding from FGDC and the NSGIC "50 States Initiative", STS - GIS Services and Applied Geographics conducted regional GIS coordination meetings and stakeholder interviews to gather detailed business requirements that support the argument of why Tennessee should invest in LiDAR/elevation GIS data products.
Here are the results from these coordination/outreach efforts:
1. What is LiDAR?
LiDAR is an optical remote sensing technology that measures properties of scattered light to find range and/or other information of a distant target. This technology is used to measure distance and derive highly accurate elevation data.
2. Does Tennessee have existing elevation data?
Yes. Through the original Tennessee Base Mapping Program (2000-2007), STS - GIS Services developed digital terrain models (DTM) primarily for ortho rectification.
3. Why does Tennessee need LiDAR "enhanced" elevation data?
While very useful, the original DTM data doesn't meet the vertical accuracy requirements for all digital elevation needs in the State.
4. What are the differences between the original DTM data and the LiDAR derived "enhanced" elevation data?
The original photogrammetric derived standard DTM data has a vertical accuracy of +/- seven feet; suitable for a 10 foot contour that meets ASPRS class 2 standards. LiDAR derived "enhanced" elevation data can achieve a vertical accuracy of up to +/- 9cm, suitable for a 1 or 2 foot contour that meets ASPRS class 1 standards.
For more FAQ's regarding LiDAR in general, please see the following document developed by USGS as part of a national assessment for enhanced elevation:
Click image to view a larger version.
Project Summary Details:
- STS GIS - USGS 3DEP 2016
- STS GIS - USGS 3DEP 2015
- USDA-NRCS West
- USDA-NRCS Cane Cr.
- USDA-NRCS Tipton County
- USDOI OSM
- Anderson County
- Hamilton County
- Knox County
- Metro-Davidson County-Mill Creek-Harpeth River
- Rutherford County
- FEMA (Risk Map) Stones River
- Univ. of GA - USGS Great Smokey Mt. Project Summary
- City of Clarksville
- USGS NGTOC - Shelby County
- STS GIS Sequatchie and Van Buren Counties
- STS GIS Scott County
LiDAR, or Light Detection and Ranging, is an evolving technology used to support a wide variety of geospatial business needs at all levels of government and in the private sector.
Instead of defining our own interpretation or understanding of LiDAR, we are providing the following URL's that best describe the technology, resources, associated elevation data products, and how to apply the technology for specific applications.