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2009 Chatham County Georgia Lidar

browse graphicThis kmz file shows the extent of coverage for the 2009 Chatham County, GA lidar data set.
LiDAR generated point cloud acquired in spring 2009 for Chatham County, Georgia for the Metropolitan Planning Commission. The data are classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 9 = Water This data is for planning purposes only and should not be used for legal or cadastral purposes.

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Point of Contact Noel Perkins
    SAGIS
    912-651-1476
    perkinsn@thempc.org
    Documentation links not available.
    Originator
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Originator
    • Chatham County, Georgia
    Publisher
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2012-01-01
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: Unknown
    Supplemental Information: Support of FEMA's Floodplain Map Modernization Program and Florida Division of Emergency Management Disaster standards. Collection parameters are as follows: Flight Altitude - 1100m (agl) Repetition Rate - 93300 kHz; Scan Frequency - 44.5kz Airspeed - 100-120 knots Field of View - 30 degrees Avg. Point Spacing 0.57m Flightline Spacing - 294m
    Purpose: LiDAR points used in conjunction with LiDAR derived breaklines to determine a DTM surface.
    Use Limitations
    • These data depict the elevations at the time of the survey and are only accurate for that time. 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be aware that temporal changes may have occurred since this data set was collected and some parts of this data may no longer represent actual surface conditions.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. Any conclusions drawn from analysis of this information are not the responsibility of NOAA or any of its partners. These data are NOT to be used for navigational purposes.
    Time Period: Unknown  to  Unknown
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: 32.250903
    S: 31.713978
    E: -80.831008
    W: -81.395700
    Spatial Coverage Map:
    Themes
    • Bathymetry/Topography
    • DTM
    • Elevation
    • Lidar
    Places
    • United States
    • Georgia
    • Chatham County
    Use Constraints No constraint information available
    Fees Fee information not available.
    Lineage Statement Lineage statement not available.
    Processor
    • Sanborn Map Company
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
    Processing Steps
    • The ABGPS, IMU, and raw Leica ALS-50 LiDAR data are integrated into the LEICA ALS post processor software. The resultant file is in a LAS binary file format. The LAS file version 1.1 formats can be easily transferred from one file format to another. It is a binary file format that maintains information specific to the LiDAR data (return#, intensity value, xyz, etc.). The resultant points are produced in the geodetic coordinates referenced to the NAD83 horizontal datum and GRS80 vertical datum.
    • The unedited data are classified to facilitate the application of the appropriate feature extraction filters. A combination of proprietary filters are applied as appropriate for the production of bare earth digital terrain models (dtms). Interactive editing methods are applied to those areas where it is inappropriate or impossible to use the feature extraction filters, based upon the design criteria and/or limitations of the relevant filters. These same feature extraction filters are used to produce elevation height surfaces. The LiDAR mass points were delivered in American Society for Photogrammetry and Remote Sensing LAS 1.1 format. The header file for each dataset is complete as define by the LAS 1.1 specification. In addition the following fields are included: Flight Date Julian, Year, and Class. The LAS files do not include an overlap class. The data was classified as follows: Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class 2 = Ground Class 7 = noise (outliers) Class 9 = Water
    • Conversion from Geodetic coordinates, NAD83 into State Plane coordinates (U.S. Survey Feet) NAD83 and conversion from ellipsoid heights (meters) into orthometric heights (U.S. Survey Feet).
    • Ground points were extracted from the Lidar dataset and used in conjunction with breaklines to hydrologically enforce a DTM surface and converted to an ESRI GRID (1m pixels) using ArcGIS.
    • The NOAA Coastal Services Center (CSC) received the files in las format. The files contained lidar elevation and intensity measurements. The data were in GA State Plane coordinates and NAVD88 (orthometric) heights in feet. CSC performed the following processing for data storage and Digital Coast provisioning purposes: 1. The data were converted from GA State Plane coordinates to geographic coordinates. 2. The data were converted from NAVD88 (orthometric) heights in feet to GRS80 (ellipsoid) heights in meters using Geoid 03. 3. The data were filtered to remove outliers. 4. The LAS data were sorted by latitude and the headers were updated.
    • The NOAA National Geophysical Data Center (NGDC) received lidar data files via ftp transfer from the NOAA Coastal Services Center. The data are currently being served via NOAA CSC Digital Coast at http://www.csc.noaa.gov/digitalcoast/. The data can be used to re-populate the system. The data are archived in LAS or LAZ format. The LAS format is an industry standard for LiDAR data developed by the American Society of Photogrammetry and Remote Sensing (ASPRS); LAZ is a loseless compressed version of LAS developed by Martin Isenburg (http://www.laszip.org/). The data are exclusively in geographic coordinates (either NAD83 or ITRF94). The data are referenced vertically to the ellipsoid (either GRS80 or ITRF94), allowing for the ability to apply the most up to date geoid model when transforming to orthometric heights.

    Metadata Last Modified: 2013-06-04

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