North Carolina Statewide Lidar DEM 2014 Phase 1

Geographic Extent: North Carolina Area of Interest for Sandy, covering approximately 9,396 square miles.

Dataset Description: The North Carolina - Sandy 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 (later changed to vertical meters). LiDAR data was delivered in RAW flight line swath format, processed to create Classified LAS 1.3 Files formatted to 12138 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.

Ground Conditions: LiDAR was collected in Spring 2014, 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, Photo Science established a total of 282 QA control points and 161 Land Cover control points that were used to calibrate the LIDAR to known ground locations established throughout the North Carolina - Sandy project area.

Data was collected under USGS Contract: G10PC00026 Task Order Number: G14PD00182 and originally had a title of "Lidar data for North Carolina - SANDY 2014". The title was modified to avoid conflict with other phases of the North Carolina collection conducted by the North Carolina Floodplain Mapping Program (NCFMP). This data was funded jointly by USGS and NCFMP.

Original contact information:

Contact Name: Michael Shillenn

Contact Org: Photo Science, Inc., Data Acquisition Department

Phone: 859-277-8700

Email: mshillenn@photoscience.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.

The purpose of these lidar data was to produce high accuracy 3D hydro-flattened Digital Elevation Model (DEM) with a 5 feet cell size.

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

12107

USGS Contract No. G10PC00026

CONTRACTOR: Photo Science, Inc

Ground Control Points were acquired and calibrated by Photo Science, Inc.

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

Please note the lrdinfo section has been repeated twice for the two different specifications used to acquire the data. This lidar section has been commented out in xml because the standard metadata schema does not include it.

Any conclusions drawn from the analysis of this information are not the responsibility

of Photo Science, USGS, NOAA, NCFMP, the 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=5005

;

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. Acknowledgment of the U.S. Geological Survey would be appreciated for products derived from these data. Acknowledgment of the NOAA Digital Coast for data distribution would also be appreciated.

None.

None.

MicroStation Version 8; TerraScan Version 13; TerraModeler Version 13; GeoCue Version 2012.1.27.7; ESRI ArcGIS 10.1; Global Mapper 13; ALS Post Processor 2.75 Build #25; Windows 7 Operating System \\psihq_nx3200\Projects\7505_089_NorthCarolina_2014LIDAR\ 2.2 TB and \\Matrix\LIDAR\7505-089_NC_LiDAR_2014 15.8 TB

The specifications require that only Fundamental Vertical Accuracy (FVA) be computed for raw lidar point cloud swath files.

The vertical accuracy value is the AccuracyZ at 95 percent Confidence Interval in feet. The FVA was tested using 282 independent survey located in open terrain. The survey checkpoints were distributed throughout the project area. The 282 independent check points were surveyed using GPS techniques. See survey report for additional survey methodologies. 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. AccuracyZ has been tested to meet 18.13 cm Fundamental Vertical Accuracy at 95 Percent confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

; Quantitative Value: 0.118 meters, Test that produced the value:

The FVA AccuracyZ in meters. The FVA was tested using 282 independent survey located in open terrain. The survey checkpoints were distributed throughout the project area. The 282 independent check points were surveyed using GPS techniques. See survey report for additional survey methodologies. 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 0.197 feet. AccuracyZ has been tested to meet 18.13 cm Fundamental Vertical Accuracy at 95 Percent confidence level using RMSE(z) x 1.9600 as defined by the National Standards for Spatial Data Accuracy (NSSDA); assessed and reported using National Digital Elevation Program (NDEP)/ASPRS Guidelines.

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 Fundamental Vertical Accuracy specifications.

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