2015 NCFMP Lidar: Statewide North Carolina (Phase 3)

Geographic Extent: North Carolina Area of Interest, covering approximately 7,197 square miles.

Dataset Description: The North Carolina LiDAR project called for the Planning, Acquisition, processing and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meter. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1. The data was developed based on a horizontal projection/datum of North Carolina State Plane Coordinate System, NAD83, survey feet and vertical datum of NAVD1988 (GEOID12A), survey feet. Lidar data was delivered in RAW flight line swath format, processed to create Classified LAS 1.4 Files formatted to 8026 individual 5000ft x 5000ft tiles, and corresponding Intensity Images and Bare Earth DEMs tiled to the same 5000ft x 5000ft schema, and Breaklines in ESRI File-Geodatabase format.

Data in 10591 tiles were received by NOAA in LAS 1.3 format and were transformed to ellipsoid heights and geographic coordinates for the Digital Coast Data Access Viewer.

Ground Conditions: LiDAR was collected in Spring 2015, while no snow was on the ground and rivers were at or below normal levels. In order to post process the LiDAR data to meet task order specifications, Quantum Spatial established a total of 71 control points that were used to calibrate the lidar to known ground locations established throughout the North Carolina project area.

Original contact information:

Contact Name: Jeff Simmons

Contact Org: Quantum Spatial, Inc., Data Acquisition Department

Phone: 859-277-8700

Email: jsimmons@quantumspatial.com

Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create Intensity Images, Breaklines and Raster DEM.

These raw lidar point cloud data were used to create classified lidar LAS files, intensity images, 3D breaklines, hydro-flattened DEMs as necessary.

10482

CONTRACTOR: Quantum Spatial, Inc

Ground Control Points were acquired and calibrated by Quantum Spatial, Inc.

All Lidar data acquisition, calibration, and follow-on processing were completed by the prime contractor.

Please note the ldrinfo section has been repeated twice for the two different specifications used to acquire the data. The section is commented out in the xml metadata in order to pass the metadata schema check at NOAA.

The following are the USGS lidar fields in JSON:

{

"ldrinfo" : {

"ldrspec" : "USGS-NGP Base Lidar Specification v1.0",

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.61",

"ldrdens" : "2.47",

"ldrfltht" : "1400",

"ldrfltsp" : "150",

"ldrscana" : "18.5",

"ldrscanr" : "42.9",

"ldrpulsr" : "195.4",

"ldrpulsd" : "4",

"ldrpulsw" : "0.32",

"ldrwavel" : "1064",

"ldrmpia" : "0",

"ldrbmdiv" : "0.22",

"ldrswatw" : "936.87",

"ldrswato" : "12.79",

"ldrcrs" : "NAD_1983_2011_StatePlane_North_Carolina_FIPS_3200_Feet",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldrinfo120knots" : {

"ldrspec" : "USGS-NGP Base Lidar Specification v1.0",

"ldrsens" : "Leica ALS 70",

"ldrmaxnr" : "4",

"ldrnps" : "0.54",

"ldrdens" : "3.09",

"ldrfltht" : "1400",

"ldrfltsp" : "120",

"ldrscana" : "18.5",

"ldrscanr" : "38.3",

"ldrpulsr" : "195.4",

"ldrpulsd" : "4",

"ldrpulsw" : "0.32",

"ldrwavel" : "1064",

"ldrmpia" : "0",

"ldrbmdiv" : "0.22",

"ldrswatw" : "936.87",

"ldrswato" : "12.79%",

"ldrcrs" : "NAD_1983_2011_StatePlane_North_Carolina_FIPS_3200_Feet",

"ldrgeoid" : "National Geodetic Survey (NGS) Geoid12A"

},

"ldraccur" : {

"ldrchacc" : "0.196",

"rawnva" : "0.074",

"rawnvan" : "148",

"clsnva" : "-9999",

"clsnvan" : "0",

"clsvva" : "-9999",

"clsvvan" : "0"

},

"lasinfo" : {

"lasver" : "1.4",

"lasprf" : "6",

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

"lasolap" : "Swath "overage" points were identified in these files using the standard LAS overlap bit",

"lasintr" : "8",

"lasclass" : {

"clascode" : "1",

"clasitem" : "Default"

},

"lasclass" : {

"clascode" : "2",

"clasitem" : "Ground"

},

"lasclass" : {

"clascode" : "3",

"clasitem" : "LowVeg/Strata"

},

"lasclass" : {

"clascode" : "4",

"clasitem" : "MediumVeg/Strata"

},

"lasclass" : {

"clascode" : "5",

"clasitem" : "HighVeg/Strata"

},

"lasclass" : {

"clascode" : "6",

"clasitem" : "Buildings(Automated)"

},

"lasclass" : {

"clascode" : "7",

"clasitem" : "LowPoints/Noise"

},

"lasclass" : {

"clascode" : "9",

"clasitem" : "Water"

},

"lasclass" : {

"clascode" : "10",

"clasitem" : "BreaklineProximity"

},

"lasclass" : {

"clascode" : "13",

"clasitem" : "Roads (Optional)"

},

"lasclass" : {

"clascode" : "14",

"clasitem" : "Bridges (Optional)"

}

}}

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

This data can be obtained on-line at the following URL:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6209.

The DEM generated as part of the contract can be obtained on-line at:

https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6205.

;

No restrictions apply to these data.

None. However, users should be aware that temporal changes may have occurred since this dataset was collected and that some parts of these data may no Longer represent actual surface conditions. Users should not use these data for critical applications without a full awareness of it's limitations. Acknowledgement of the U.S. Geological Survey and the North Carolina Flood Mapping Program would be appreciated for products derived from these data.

MicroStation Version 8; TerraScan Version 15; TerraModeler Version 15; GeoCue Version 2014.1.21.2; ESRI ArcGIS 10.2.2; Global Mapper 15.2; ALS Post Processor 2.75 Build #25; Leica Cloud Pro Version 1.2.1; Windows 7 Operating System \\psihq_nx3200\Projects\25481_NC_Lidar_2015\ 794 GB and \\Matrix\lidar\25481_NC_LiDAR_2015\ 8.37 TB

The specifications require that only Nonvegetated Vertical Accuracy (NVA) be computed for raw lidar point cloud swath files. The vertical accuracy was tested with 148 independent survey located in open terrain. These check points (check points) were not used in the calibration or post processing of the lidar point cloud data. The survey check points were distributed throughout the project. Specifications for this project require that the NVA be 18.13 cm or better AccuracyZ at 95 percent confidence level.; Quantitative Value: 0.074 meters, Test that produced the value: The NVA was tested using 148 independent surveys located in open terrain. The survey check points were distributed throughout the project area. The 148 independent check points were surveyed using the closed level loop technique. Elevations from the unclassified lidar surface were measured for the x,y location of each check point. Elevations interpolated from the lidar surface were then compared to the elevation values of the surveyed control. The RMSE was computed to be 0.124 feet. AccuracyZ has been tested to meet 18.13 cm Nonvegetated Vertical Accuracy at 95 percent confidence level using (RMSEz * 1.9600) as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines. AccuracyZ in meters is 0.074.

Datasets contain complete coverage of tiles.

No points have been removed or excluded.

A visual qualitative assessment was performed to ensure data completeness.

There are no void areas or missing data. The raw point cloud is of good quality and data passes Non-Vegetated Vertical Accuracy specifications.

Classified LAS files were tested by Quantum Spatial for both vertical and horizontal accuracy. All data is seamless from one tile to the next, no gaps or no data areas.