Data Management Plan

The Digital Elevation Models (DEM) were generated at a 3.125 foot resolution as rasters, using the ground (Class 2) points and the hydro flattened breaklines as inputs from the project. The DEMs were produced specific to the 2016 Phase Four project area consisting of 20 North Carolina counties. LiDAR data for the project and the validation site was collected by a single aerial vendor on ESP team between February 27, 2016 and April 17, 2016 and between December 9, 2016 and February 21 of 2017 using Geiger-mode Avalanche Photodiode (GmAPD) sensors. The aerial vendor on the ESP team was Harris Corporation (Harris).Two GmAPD (Geiger-mode) sensors (serial numbers 002 and 003) were used for the data collection of LiDAR data at a 0.35 meter nominal post spacing (NPS). The following counties or portions of counties were collected in the February through April, 2016 mobilization: Alleghany, Stokes, Surry, Cleveland, Gaston, Mecklenburg, Cabarrus, Stanly, Union, and Anson. The following counties or portions of counties we collected in the December, 2016 through February, 2017 mobilization: Cleveland, Gaston, Mecklenburg, Cabarrus, Stanly, Wilkes, Yadkin, Forsyth, Alexander, Catawba, Iredell, Davie, Rowan, and Davidson. All data was collected during leaf-off conditions. Ground survey support for the project included the establishment of GPS base stations and the collection of control points used for calibration. All data was delivered in the North Carolina State Plane Coordinate System, with a horizontal datum of NAD83 (2011), vertical datum of NAVD88 (Geoid 12B), in US Survey Feet. Data was delivered tiled to a 2,500 foot by 2,500 foot tiling scheme unless otherwise specified in this product description. All LiDAR was delivered in LASer (LAS) version 1.4 standard format. Products for this project derived from the source LiDAR included: intensity images in GeoTIFF format, hydro-flattening breaklines in ESRI File Geodatabase format, Digital Elevation Models (DEMs) in TIF format, ESRI Terrain Datasets (by county) in ESRI File Geodatabase format, product and project-level metadata, and project reports to include the Report of Survey, Post-Acquisition Report, and Project Report. All LiDAR and derivative products for this project met the specifications stipulated in Delivery Order 22, the NC LiDAR Standard, and the USGS minimum standards for QL1 LiDAR data. This project was a joint effort between NC Emergency Management, NC Geodetic Survey, and the NCDOT. The following people served as the main representatives for each stakeholder: NC Emergency Management- Hope Morgan (primary contact) and John Dorman; NC Geodetic Survey- Gary Thompson and Watson Ross; NCDOT- Keith Johnston and Marc Swartz, and the United States Geological Survey (USGS.

Process Steps:

• 2017-01-01 00:00:00 - Hydro Flattened Raster DEMs were generated using the Class 2 (ground) lidar points in conjunction with the hydro breaklines to create a 3.125 foot hydro-flattened Raster DEM. Using automated batch routines in ESP Utilities, an TIF file was created for each tile of the project. DEM surface was reviewed using ESP Analyst to check for any surface anomalies or incorrect elevations found within the surface (Citation: Lidar Point cloud: NC 2016 Phase 4)
• 2022-01-25 00:00:00 - Data were downloaded from the USGS, unzipped, and converted to cloud optimized Geotiff format. They were ingested into the Digital Coast Data Access Viewer for custom download. (Citation: DEM zip files)

Data is available online for bulk or custom downloads