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Short Citation:
OCM Partners, 2023: 2009 USACE NCMP Topobathy Lidar DEM: North Carolina, https://www.fisheries.noaa.gov/inport/item/67632.

Item Identification

Title: 2009 USACE NCMP Topobathy Lidar DEM: North Carolina
Short Name: usace2009_nc_dem_m9565_metadata
Status: Completed
Creation Date: 2009
Abstract:

These files contain rasterized topographic lidar elevations generated from returns classified as ground (2). These data were collected by the Compact Hydrographic Airborne Rapid Total Survey (CHARTS) system along the coast of North Carolina. CHARTS integrates topographic and bathymetric lidar sensors, a digital camera and a hyperspectral imager on a single remote sensing platform for use in coastal mapping and charting activities. Data coverage generally extends along the coastline from the waterline inland 500 meters (topography) and offshore 1,000 meters or to laser extinction (bathymetry). Native lidar data is not generally in a format accessible to most Geographic Information Systems (GIS). Specialized in-house and commercial software packages are used to processes the native lidar data into 3-dimensional positions that can be imported into GIS software for visualization and further analysis. The 3-D position data are used to generate a series of gridded file products, with each covering approximately 5 kilometers of shoreline. The data file naming convention is based on the year, project, area name, "Box" number and the product type. An example file name is "2009_NCMP_NC_01_BareEarth_1mGrid.tif", where 2009 is the year of data collection, NCMP is the project under which data were collected, NC is the area of data collection, 01 is the "Box" number and "BareEarth_1mGrid" is the product type.

In addition to these bare earth Digital Elevation Model (DEM) data, the lidar point data that these DEM data were created from, are also available. These data are available for custom download at the link provided in the URL section of this metadata record.

Purpose:

These data were collected as a part of the NCMP to depict the elevations above and below water in the North Carolina coastal zone.

Keywords

Theme Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > LAND SURFACE > TOPOGRAPHY > TERRAIN ELEVATION > DIGITAL ELEVATION/TERRAIN MODEL (DEM)
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > BATHYMETRY/SEAFLOOR TOPOGRAPHY > BATHYMETRY > COASTAL BATHYMETRY
Global Change Master Directory (GCMD) Science Keywords
EARTH SCIENCE > OCEANS > COASTAL PROCESSES > COASTAL ELEVATION
ISO 19115 Topic Category
elevation
ISO 19115 Topic Category
imageryBaseMapsEarthCover
ISO 19115 Topic Category
oceans

Spatial Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA
Global Change Master Directory (GCMD) Location Keywords
CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA > NORTH CAROLINA
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > LAND SURFACE
Global Change Master Directory (GCMD) Location Keywords
VERTICAL LOCATION > SEA FLOOR
UNCONTROLLED
Geographic Names Information System Carteret County
Geographic Names Information System Currituck County
Geographic Names Information System Dare County
Geographic Names Information System Elizabeth City
Geographic Names Information System Havelock
Geographic Names Information System Hyde County

Instrument Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Instrument Keywords
LIDAR > Light Detection and Ranging

Platform Keywords

Thesaurus Keyword
Global Change Master Directory (GCMD) Platform Keywords
AIRCRAFT

Physical Location

Organization: Office for Coastal Management
City: Charleston
State/Province: SC

Data Set Information

Data Set Scope Code: Data Set
Data Set Type: Elevation
Maintenance Frequency: As Needed
Data Presentation Form: Model (digital)
Distribution Liability:

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

Data Set Credit: JALBTCX (Joint Airborne Lidar Bathymetry Technical Center of eXpertise)

Support Roles

Data Steward

CC ID: 1179858
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Distributor

CC ID: 1179857
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Metadata Contact

CC ID: 1179859
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Point of Contact

CC ID: 1179860
Date Effective From: 2022
Date Effective To:
Contact (Organization): NOAA Office for Coastal Management (NOAA/OCM)
Address: 2234 South Hobson Ave
Charleston, SC 29405-2413
Email Address: coastal.info@noaa.gov
Phone: (843) 740-1202
URL: https://coast.noaa.gov

Extents

Currentness Reference: Ground Condition

Extent Group 1

Extent Group 1 / Geographic Area 1

CC ID: 1179923
W° Bound: -76.543732
E° Bound: -75.460732
N° Bound: 36.550949
S° Bound: 34.585149

Extent Group 1 / Time Frame 1

CC ID: 1179862
Time Frame Type: Range
Start: 2009-08-16
End: 2009-08-24

Spatial Information

Spatial Representation

Representations Used

Grid: Yes

Reference Systems

Reference System 1

CC ID: 1179921

Coordinate Reference System

CRS Type: Geographic 2D
EPSG Code: EPSG:4269
EPSG Name: NAD83
See Full Coordinate Reference System Information

Reference System 2

CC ID: 1179922

Coordinate Reference System

CRS Type: Vertical
EPSG Code: EPSG:5703
EPSG Name: NAVD88 height
See Full Coordinate Reference System Information

Access Information

Security Class: Unclassified
Data Access Procedure:

Data is available online for bulk and custom downloads.

Data Access Constraints:

None

Data Use Constraints:

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.

Distribution Information

Distribution 1

CC ID: 1179864
Start Date: 2022-08-08
End Date: Present
Download URL: https://chs.coast.noaa.gov/htdata/raster5/elevation/USACE_NC_DEM_2009_9565
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Bulk Download
Description:

Bulk download of data files in the original coordinate system.

File Type: GeoTIFF

Distribution 2

CC ID: 1179863
Start Date: 2022-08-08
End Date: Present
Download URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=9565/details/9565
Distributor: NOAA Office for Coastal Management (NOAA/OCM) (2022 - Present)
File Name: Customized Download
Description:

Create custom data files by choosing data area, map projection, file format, etc. A new metadata will be produced to reflect your request using this record as a base.

File Type: Zip
Compression: Zip

URLs

URL 1

CC ID: 1179854
URL: https://coast.noaa.gov/
Name: NOAA's Office for Coastal Management (OCM) website
URL Type:
Online Resource
File Resource Format: HTML
Description:

Information on the NOAA Office for Coastal Management (OCM)

URL 2

CC ID: 1179855
URL: https://coast.noaa.gov/dataviewer/
Name: NOAA's Office for Coastal Management (OCM) Data Access Viewer (DAV)
URL Type:
Online Resource
File Resource Format: HTML
Description:

The Data Access Viewer (DAV) allows a user to search for and download elevation, imagery, and land cover data for the coastal U.S. and its territories. The data, hosted by the NOAA Office for Coastal Management, can be customized and requested for free download through a checkout interface. An email provides a link to the customized data, while the original data set is available through a link within the viewer.

URL 3

CC ID: 1179924
URL: https://coast.noaa.gov/htdata/raster5/elevation/USACE_NC_DEM_2009_9565/supplemental/usace2009_nc_dem_m9565.kmz
Name: Browse Graphic
URL Type:
Browse Graphic
File Resource Format: KML
Description:

This graphic displays the footprint for this lidar data set.

URL 4

CC ID: 1179925
URL: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=8609/details/8609
Name: Custom Point Download
URL Type:
Online Resource
File Resource Format: Zip
Description:

Link to custom download, from the Data Access Viewer (DAV), the lidar point data from which these raster Digital Elevation Model (DEM) data were created.

Technical Environment

Description:

Microsoft Windows Vista Version 6.1 (Build 7600) ; ESRI ArcCatalog 9.3.0.1770

Data Quality

Horizontal Positional Accuracy:

The data positions were obtained using post processed KGPS methods. The horizontal accuracy of the data is better than +/- 0.75 m at 1 Sigma

Vertical Positional Accuracy:

The data positions were obtained using post processed KGPS methods. The vertical accuracy of the data is better than +/- 0.20 m at 1 Sigma

Conceptual Consistency:

The data provided in this file were tested against ground truth data. At these locations the lidar data matched within 0.20 meters, and different flight line data agreed within 0.20 meters.

Lineage

Lineage Statement:

The USACE collected, processed, and provided the data to the NOAA Office for Coastal Management (OCM). OCM received the data and processed it to be available for custom download from the Data Access Viewer (DAV) and for bulk download from https.

Sources

USACE JALBTCX

CC ID: 1179927
Contact Role Type: Originator
Contact Type: Organization
Contact Name: USACE JALBTCX

Process Steps

Process Step 1

CC ID: 1179849
Description:

These data were collected using the CHARTS system. It is owned by the Naval Oceanographic Office and operated through contract. The system collects topographic lidar data at 9 kHz, bathymetric lidar data at 1 kHz and RGB imagery at 1Hz. A CASI-1500 hyperspectral line scanner is integrated with the system as well. Aircraft position, velocity and acceleration information are collected through a combination of Novatel and POS A/V 410 equipment. All raw data streams are transferred to the office for downloading and processing in SHOALS GCS software. Aircraft position data are processed using POSPac software and the results are combined with the lidar data to produce 3-D positions for each lidar shot. Upon inspection and QA/QC in the software packages Fledermaus and PFM_ABE, anomalous data are flagged as invalid. PFM_ABE's chartsLAS module then converts all valid data from ellipsoid to orthometric heights based on the NGS' GEOID03 model and exports data as a series of first return topography (TF), last return topography (TL) and bathymetry (H) ASCII files. The bathymetry files contain all of the returns from the bathymetric sensor which include returns both above and below the water. The topographic data are also exported as a series of LAS files. There is one LAS file per flightline per 5-km NCMP box.

Process Step 2

CC ID: 1179850
Description:

The flightline LAS files were imported into TerraScan V11 module within MicroStation V8.0. For each 5-km NCMP box, the points classified as first return are exported to an ASCII file with for all the flighline within the box are exported by running the macro Dump_Geo_TF.mac. This process is repeated for the points classified as last return by running the macro Dump_Geo_TL.mac.

Process Step 3

CC ID: 1179851
Description:

The flightline LAS files are imported into the TerraScan V11 module within MicroStation V8.0. The resulting LAS files are thinned to eliminate duplicate points. A customized classification macro is used to distinguish ground points (2) and unclassified points (1). The classification results are QC'd and any misclassified points are manually edited. In areas of dense vegetation the bare ground points might be incorrectly classified due to the inability of the laser to penetrate the canopy and reach the bare ground. In these areas, JALBTCX defaults to the algorithm's "ground" surface instead of manually reclassifying those points. The points are exported to an ASCII file containing the following fields: longitude, latitude, elevation (orthometric), intensity, classification, mirror angle, time (GPS time), number of echos, and echo number. The ASCII file is converted to LAS using txt2las code from LAStools (http://www.cs.unc.edu/~isenburg/lastools/).

Process Step 4

CC ID: 1179852
Description:

The points classified as ground in the Classified LAS files are exported from TerraScan V11 and converted to a grid by generating a Triangulated Irregular Network (TIN) and the extracting the grid node elevations from the TIN surface. The origin point of the grid is located at a horizontal position whose value is evenly divisible by the 1m grid resolution such that rasters from subsequent surveys have common cell boundaries. JALBTCX uses Quick Terrain Modeler V7.1.1 to perform this operation utilizing the following key parameters; “Max Sample Excursion 50,” “Max Triangle Side 100,” “Smoothing filter Level 4 with a Max Roughness 2, and "Tiling Settings Snap to Grid (Expand).” The grid is exported from Quick Terrain Modeler as an ESRI ASCII Z grid file. Utilizing an in-house python script within ESRI ArcMap V10, the ASCII Z grid file is converted to a tiff-format raster file whose projection is defined as “The North American Datum of 1983.”

Process Step 5

CC ID: 1179926
Description:

The NOAA Office for Coastal Management (OCM) received GeoTiff format files from USACE JALBTCX for the North Carolina coastline project area. The bare earth raster files were at a 1 m grid spacing. The data were in geographic NAD83 coordinates and NAVD88 (Geoid03) elevations in meters. OCM assigned the appropriate EPSG codes (Horiz - 4269, Vert - 5703) and copied the raster files to https for Digital Coast storage and provisioning purposes.

Process Date/Time: 2022-08-08 00:00:00
Process Contact: Office for Coastal Management (OCM)

Related Items

Item Type Relationship Type Title
Data Set (DS) Cross Reference 2009 USACE NCMP Topobathy Lidar: Atlantic Coast (NC, VA)

Catalog Details

Catalog Item ID: 67632
GUID: gov.noaa.nmfs.inport:67632
Metadata Record Created By: Rebecca Mataosky
Metadata Record Created: 2022-08-08 19:54+0000
Metadata Record Last Modified By: Rebecca Mataosky
Metadata Record Last Modified: 2022-10-05 13:35+0000
Metadata Record Published: 2022-08-08
Owner Org: OCMP
Metadata Publication Status: Published Externally
Do Not Publish?: N
Metadata Last Review Date: 2022-08-08
Metadata Review Frequency: 1 Year
Metadata Next Review Date: 2023-08-08