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2011 Georgia Department of Natural Resources (GADNR) Environmental Protection Division (EPD) Lidar: Four Counties (Burke, Columbia, Lincoln, and Richmond)

browse graphicThis kmz file shows the extent of coverage for the 2011 Georgia DNR 4 Counties lidar data set.
This data set is the topographic elevation point data derived from multiple return light detection and ranging (LiDAR) measurements for four counties in Georgia. These counties are: Burke, Columbia, Lincoln, and Richmond. The Statement of Work (SOW) was developed by the National Oceanic and Atmospheric Administration's (NOAA) Coastal Services Center (referred to as the Center) in partnership with the Georgia Department of Natural Resources (GADNR) Environmental Protection Division (EPD). LiDAR data is a remotely sensed high resolution elevation data collected by an airborne platform. The LiDAR sensor uses a combination of laser range finding, GPS positioning, and inertial measurement technologies. The LiDAR systems collect data point clouds that are used to produce highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation. The LiDAR data acquisition and processing for Burke, Lincoln, and Richmond County was performed in the Winter of 2011. The LiDAR data was provided to NOAA CSC, as part of the 4 GA Counties of Elevation Data task order. The 4 GA Counties of Elevation Data task order AOI encompassed approximately 1,739 square miles. The area of interest acquired and processed for Burke, Lincoln, and Richmond County is approximately 1,386 square miles. The task order required the LiDAR data to be collected at a nominal pulse spacing (NPS) of 1.0 meter. The LiDAR data was collected to meet Fundamental Vertical Accuracy (FVA) Root Mean Square Error (RMSE) of 18.0 cm or better at a 95% confidence level, so that when combined with breaklines, the data adequately supports the generation of two (2) foot FEMA compliant contours. The final LiDAR data was delivered in 5,000' x 5,000' tiles using North American Datum 1983, Georgia State Plane Coordinate System, East Zone, and expressed in US Survey Feet. For data storage and Digital Coast provisioning purposes, the NOAA CSC converted the data to geographic coordinates and ellipsoid heights in meters. Special Note: Temporal changes of water levels will be observed in any data from Richmond and Lincoln counties overlapping any previously delivered data from Columbia County. The final products include full classified LAS, hydrologically flattened four (4) foot pixel raster DEM's of the bare earth surface in ESRI Floating Point Grid Format (ArcGRID DEMs), and hydrologically flattened breaklines. The data were collected on the following dates: Burke and Richmond Counties: December 13, 14, 17, 2011 Columbia County February 26, 2011 Lincoln County December 18, 2011 The data contains las points with the following classifications: Class 0 No Classification Class 2 Ground Class 7 Low Point (Noise) Class 9 Water Class 10 Land below sea level Class 12 Overlap

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Point of Contact DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    843-740-1200
    coastal.info@noaa.gov
    Documentation links not available.
    Originator
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Originator
    • Georgia Department of Natural Resources (GADNR)
    Publisher
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2012-09-01
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: As needed
    Purpose: The purpose of this data is for use in coastal management decision making, including applications such as flood mapping, hydrologic modeling, risk map analysis, and water rights management.
    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: 2011-12-13  to  2012-02-26
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: 33.982767
    S: 32.797092
    E: -81.540949
    W: -82.641278
    Spatial Coverage Map:
    Themes
    • Bathymetry/Topography
    • Model
    • DEM
    • Raster
    • Breaklines
    • Remote Sensing
    • Elevation
    • LiDAR
    Places
    • United States
    • Georgia
    • Burke County
    • Columbia County
    • Lincoln County
    • Richmond County
    Use Constraints No constraint information available
    Fees Fee information not available.
    Lineage Statement Lineage statement not available.
    Processor
    • Woolpert, Inc.
    • DOC/NOAA/NOS/OCM > Office for Coastal Management, 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
    • Using a Leica LiDAR system, 100 flight lines of high density data, at a nominal pulse spacing (NPS) of 1.0 meter, were collected over Burke, Lincoln and Richmond Counties, GA (approximately 1,386 square miles). Multiple returns were recorded for each laser pulse along with an intensity value for each return. A total of six (6) missions were flown on December 13, 14, 17, and 18 in 2011. The geoid used to reduce satellite derived elevations to orthometric heights was Geoid09. The horizontal datum used for this survey is North American Datum 1983, Georgia State Plane Coordinate System, East Zone, and expressed in US Survey Feet. The vertical datum used for this survey is North American Vertical Datum 1988 (NAVD88), and expressed in US Survey Feet. Airborne GPS data was differentially processed and integrated with the post processed IMU data to derive a smoothed best estimate of trajectory (SBET). The SBET was used to reduce the LiDAR slant range measurements to a raw reflective surface for each flight line. System Parameters: Type of Scanner = Leica Data Acquisition Height = 6,500-feet AGL Scanner Field of View = 40 degrees The Scan Frequency = 41.8 Hertz Pulse Repetition Rate - 115.6 Kilohertz Aircraft Speed = 130 Knots Swath Width = 4,732-feet Number of Returns Per Pulse = Maximum of 4 Distance Between Flight Lines = 3,289-feet
    • The Leica ALS50/60 LiDAR systems calibration and performance is verified on a periodic basis using Woolpert's calibration range. The calibration range consists of a large building and runway. The edges of the building and control points along the runway have been located using conventional survey methods. Inertial measurement unit (IMU) misalignment angles and horizontal accuracy are calculated by comparing the position of the building edges between opposing flight lines. The scanner scale factor and vertical accuracy is calculated through comparison of LiDAR data against control points along the runway. Field calibration is performed on all flight lines to refine the IMU misalignment angles. IMU misalignment angles are calculated from the relative displacement of features within the overlap region of adjacent (and opposing) flight lines. The raw LiDAR data is reduced using the refined misalignment angles.
    • Once the data acquisition and GPS processing phases are complete, the LiDAR data was processed immediately to verify the coverage had no voids. The GPS and IMU data was post processed using differential and Kalman filter algorithms to derive a best estimate of trajectory. The quality of the solution was verified to be consistent with the accuracy requirements of the task order.
    • The individual flight lines were inspected to ensure the systematic and residual errors have been identified and removed. Then, the flight lines were compared to adjacent flight lines for any mismatches to obtain a homogenous coverage throughout the project area. The point cloud underwent a classification process to determine bare-earth points and non-ground points utilizing "first and only" as well as "last of many" LiDAR returns. This process determined bare-earth points (Class 2), noise (Class 7), water (Class 9) ignored ground (Class 10), unclassified data (Class 1), and overlap points (Class 12). The bare-earth (Class 2 - Ground) LiDAR points underwent a manual QA/QC step to verify that artifacts have been removed from the bare-earth surface. The surveyed ground control points are used to perform the accuracy checks and statistical analysis of the LiDAR dataset.
    • Breaklines defining lakes, greater than two acres, and double-line streams, wider than 100 feet (30.5 meters), were compiled using digital photogrammetric techniques as part of the hydrographic flattening process and provided as a geodatabase containing ESRI Polyline Z and Polygon Z feature classes. Breaklines defining water bodies and streams were compiled for this task order. The breaklines were used to perform the hydrologic flattening of water bodies, and gradient hydrologic flattening of double line streams. Lakes, reservoirs and ponds, at a nominal minimum size of two (2) acres or greater, were compiled as closed polygons. The closed water bodies were collected at a constant elevation. Rivers and streams, at a nominal minimum width of 100 feet (30.5 meters), were compiled in the direction of flow with both sides of the stream maintaining an equal gradient elevation. The hydrologic flattening of the LiDAR data was performed for inclusion in the National Elevation Dataset (NED). For this specific project, NOAA requested that Woolpert define the Strom Thurmond Reservoir using a contour set to match the water level used for the portion of the reservoir located in Columbia County. This elevation is 323.55 survey feet. The Columbia county data was acquired several months prior to the Burke, Richmond, and Lincoln Counties. Due to this, the water levels in the reservoir were different. Woolpert set the contour to 325.55 survey feet and classified the las and produced the required products using the contour derived Strom Thurmond Reservoir.
    • The NOAA Coastal Services Center (CSC) received the files in las format. The files contained lidar elevation and intensity measurements. The data were in State Plane projection (NAD83, Georgia East), and vertically referenced to NAVD88 using the Geoid 09 model. Both horizontal and vertical units were in survey feet. CSC performed the following processing for data storage and Digital Coast provisioning purposes: 1. The data were converted from Georgia State Plane coordinates to geographic (NAD83) coordinates. 2. The data were converted from orthometric (NAVD88) heights to ellipsoidal heights (GRS80) using Geoid09. 3. The data were converted from vertical units of survey feet to meters. 4. Elevation outliers were removed. 5. The data were converted to LAZ format.
    • 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: 2013-01-22

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