2017 NCEM NCDOT USGS Lidar: NC Statewide Phase 5

The data set was collected specific to the 2017 Phase Five project area consisting of 21 North Carolina counties. LiDAR data for the project and the validation site was collected by a single aerial vendor on ESP team between February 10, 2017 and April 10, 2017 using Geiger-mode Avalanche Photodiode (GmAPD) sensors. The aerial vendor on the ESP team was Harris Corporation (Harris).Three GmAPD (Geiger-mode) sensors (serial numbers 001,002 and 003) were used for the data collection of LiDAR data at a 0.35 meter nominal post spacing (NPS). The following counties were collected in the February through April, 2017 collection: Ashe, Avery, Buncombe, Burke, Caldwell, Cherokee, Clay, Graham, Haywood, Henderson, Jackson, Macon, Madison, McDowell, Mitchell, Polk, Rutherford, Swain, Transylvania, Watauga and Yancey. 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 LiDAR and derivative products for this project met the specifications stipulated in Delivery Order 35, 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).

This metadata supports the data entry in the NOAA Digital Coast Data Access Viewer (DAV). For this data set, the DAV is leveraging the Entwine Point Tiles hosted on AWS.

The purpose of this project was to update existing LiDAR data, originally collected between 2000 and 2005, with more accurate and clearly defined LiDAR data utilizing the latest in sensor technology. Although created for the North Carolina Floodplain Mapping Program for specific use in the engineering aspects of floodplain delineation, the data were also developed to address the elevation data requirements of the broader geospatial community. The North Carolina Floodplain Mapping Program was established in response to the extensive damage caused by Hurricane Floyd in 1999.

NCEM GTM Contract No. 286-000030 ESP CONTRACTOR: ESP Associates SUBCONTRACTORS: Harris Corporation, Greenman-Pederson Inc., Surdex Corporation. Lidar data were acquired and calibrated by Harris Corporation. All follow-on processing was completed by the prime contractor and subcontractors Harris Corporation, Greenman-Pederson Inc., and Surdex Corporation .

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "North Carolina Emergency Management Hybrid Specifications 2016",

"ldrsens" : "IntelliEarth GmAPD LiDAR",

"ldrmaxnr" : "1",

"ldrnps" : "0.35",

"ldranps" : "8",

"ldrdens" : "8",

"ldradens" : "8",

"ldrfltht" : "5182",

"ldrfltsp" : "220",

"ldrscana" : "15",

"ldrscanr" : "16",

"ldrpulsr" : "50",

"ldrpulsd" : "0.5",

"ldrpulsw" : "0.15",

"ldrwavel" : "1064",

"ldrmpia" : "0",

"ldrbmdiv" : "0.035",

"ldrswatw" : "2390",

"ldrswato" : "55",

"ldrcrs" : "NAD_1983_2011_StatePlane_North_Carolina_FIPS_3200_Feet",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12B"

},

"ldraccur" : {

"ldrchacc" : "0",

"rawnva" : "0",

"rawnvan" : "0",

"clsnva" : "0",

"clsnvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

"laswheld" : "Withheld (ignore) points were identified in these files using the standard LAS Withheld bit.",

"lasolap" : "Standard LAS overlap bit not used due to 55 percent overlap project design",

"lasintr" : "5",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Processed, but Unclassified"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Bare Earth Ground"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "Low Vegetation 0.5 to 3 feet"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "Medium Vegetation 3 to 10 feet"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "High Vegetation 10 to 220 ft"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Building 800 square feet or larger, automated filter"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "Noise, Low"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "Breakline Proximity"

},

"lasclass" : {

"clascode" : "11",

"clasitem" : "Noise, High"

},

"lasclass" : {

"clascode" : "13",

"clasitem" : "Roads, NCDOT assets"

},

"lasclass" : {

"clascode" : "14",

"clasitem" : "Bridges, NCDOT assets"

}

}}

Any conclusions drawn from the analysis of this information are not the responsibility of NOAA, the Office for Coastal Management or its partners.

Data is available online for bulk and custom downloads.

None

Users should be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions. Users should not use this data for critical applications without a full awareness of its limitations.

MicroStation Connect Version 10.11; TerraScan Version 19.003; ESRI ArcGIS 10.4.1, Windows 7 Operating System, ESP Analyst, ESP Utilities

This data set was produced to meet ASPRS Positional Accuracy Standard for Digital Geospatial Data (2014) for a 10-cm RMSEz Vertical Accuracy Class.

The North Carolina Geodetic Survey performed a vertical quality control (QC) survey in Phases 4 and 5 of the statewide LiDAR elevation project. The purpose of the survey was to test the elevation points contained in a dataset that was obtained by utilizing airborne Light Detection And Ranging (LiDAR) technology. The QC test points were collected utilizing the North Carolina Real Time Network (NCRTN), and with conventional survey methods in areas unsuitable for GNSS observations. Please refer to the Vertical Accuracy report for further information. A link to this report is provided in the URL section of this metadata record.

NVA = 0.262 ft (8 cm) RMSEz

VVA = 0.380 ft (11.6 cm) RMSEz

These LAS data files include all data points collected. No points have been removed or excluded. A visual qualitative assessment was performed to ensure data completeness. No void areas or missing data exist. The point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

ESP Associates tested the classified LAS files for both vertical and horizontal accuracy. All data covers the project area, tile to tile with no gaps or no data areas exceeding specifications

Data is backed up to tape and to cloud storage.

The NOAA Office for Coastal Management (OCM) ingested references to the USGS Entwine Point Tiles (EPT) hosted on Amazon Web Services (AWS) into the Digital Coast Data Access Viewer (DAV). The DAV accesses the point cloud as it resides on AWS under the usgs-lidar-public-container.