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2007 Northwest Florida Water Management District (NWFWMD) Lidar: Portions of Bay, Calhoun, Jackson and Washington Counties

LIDAR data is remotely sensed high-resolution elevation data collected by an airborne collection platform. Using a combination of laser range finding, GPS positioning and inertial measurement technologies; LIDAR instruments are able to make highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures and vegetation. Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 262 flight lines of high density (submeter ground sample distance) data were collected over areas in Bay, Calhoun, Jackson and Washington Counties in Florida. This data set was collected at the same time as the collection for Jefferson County, FL. Collectively, these data sets cover approximately 1201 square miles. The data acquisition occurred in 17 missions between February 22, 2007 and March 13, 2007. Multiple returns were recorded for each laser pulse along with an intensity value for each return. This data was collected at sub-meter resolution to provide average point spacing of 0.7 m for collected points. Up to 5 returns were recorded for each pulse in addition to an intensity value.

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 John Crowe
    Northwest Florida Water Management District (NWFWMD)
    850-539-5999
    john.crowe@nwfwmd.state.fl.us
    Associated Resources
    • Lidar Final Report
    • Lidar QA/QC Report
    Originator
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Originator
    • Northwest Florida Water Management District (NWFWMD)
    Publisher
    • DOC/NOAA/NOS/CSC > Coastal Services Center, National Ocean Service, National Oceanic and Atmospheric Administration, U.S. Department of Commerce
    Date(s)
    • publication: 2007-11-05
    Data Presentation Form: Digital image
    Dataset Progress Status Complete
    Data Update Frequency: Not planned
    Supplemental Information: Reflective surface data represents the DEM created by laser energy reflected from the first surface encountered by the laser pulse. Some energy may continue beyond this initial surface to be reflected by a subsequent surface as represented by the Last Return data. Intensity information is captured from the Reflective Surface pulse and indicates the relative energy returned to the sensor as compared to the energy transmitted. The Intensity image is not calibrated or normalized but indicates differences in energy absorption due to the interaction of the surface materials with laser energy at the wavelength transmitted by the sensor. Points are classified as on ground surface or not on ground surface to support creation of a bare earth model from the data. Points in the filtered ground class determined to be in open waterways or water bodies were reclassified as Water.
    Purpose: The data was collected to support regulatory, land management and acquisition, planning, engineering, and habitat restoration projects. It will also support the creation of Federal Emergency Management Agency Flood Insurance Rate Maps (FEMA FIRM) and an integrated ground surface model for portions of these counties.
    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: 2007-02-22  to  2007-03-13
    Spatial Reference System: urn:ogc:def:crs:EPSG::4269 Ellipsoid in Meters
    Spatial Bounding Box Coordinates:
    N: 30.647342
    S: 30.137242
    E: -85.294776
    W: -85.891976
    Spatial Coverage Map:
    Themes
    • Bathymetry/Topography
    • Elevation
    • Lidar
    • GRID
    • Digital Elevation Model
    • DEM
    • Surface Model
    Places
    • United States
    • Florida
    • Bay County
    • Calhoun County
    • Jackson County
    • Washington County
    Use Constraints No constraint information available
    Fees Fee information not available.
    Source Datasets
    • 2007 Northwest Florida Water Management District (NWFWMD) Lidar: Portions of Bay, Calhoun, Jackson and Washington Counties
      • Description of Source: Source Contribution: Type of LiDAR Scanner = LH Systems ALS50 Data Acquisition Height = 700 meters AGL Scanner Field Of View = 40 degrees Scan Frequency = 35 Hertz Pulse Repetition Rate - 50 Kilohertz Aircraft Speed = 120 KIAS Swath Width = +/- 20 degrees Nominal Ground Sample Distance = 0.7 meters Number of Returns per Pulse = 5 (first, last, intermediate) Distance Between Flight Lines = 365 meters Source Type: Digital Tape Media
      • Temporal extent used:  unknown  to 
    Lineage Statement Lineage statement not available.
    Processor
    • Sanborn
    • 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
    • Data Collection: Using a LH Systems ALS50 Light Detection And Ranging (LiDAR) system, 262 flight lines of high density (submeter ground sample distance) data were collected over areas in Bay, Calhoun, Jackson and Washington Counties in Florida. This data set was collected at the same time as the collection for Jefferson County, FL. Collectively, these data sets cover approximately 1201 square miles. The data acquisition occurred in 17 missions between February 22, 2007 and March 13, 2007. Multiple returns were recorded for each laser pulse along with an intensity value for each return. During the LIDAR campaign, the Sanborn field crew conducted a GPS field survey to establish final coordinates of the ground base stations for final processing of the base-remote GPS solutions. Four (4) airborne global positioning system (GPS) base stations were used to support the LiDAR data acquisition. GPS ground control check points were also collected by the LiDAR team while onsite for product accuracy validation and delivery.
    • Airborne GPS Processing: 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. The overlap between flight lines was removed to provide a homogeneous coverage, and the coverage was classified to extract a bare earth digital elevation model (DEM). Airborne GPS is differentially processed using the GrafNAV V7.50 software by Waypoint Consulting of Calgary, Alberta, Canada. The PDOP and distance separation is as follows: IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada. The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia. The classification and quality control (QC) of LiDAR data is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland.
    • IMU data Processing: IMU data provides information concerning roll, pitch and yaw of collection platform during collection event. IMU information allows the pulse vector to be properly placed in 3D space allowing the distance from the aircraft reference point to be properly positioned on the elevation model surface. IMU data is processed using the PosPac V4.2 software by Applanix Corporation of Richmond Hill, Ontario, Canada.
    • Reflective Surface Generation: The reflective surface is derived using the ALS Post Processor software by Leica Geosystems GIS & Mapping Division of Atlanta, Georgia.
    • LIDAR Ground Point Classification: The classification and quality control (QC) of LiDAR Ground point class is carried out using TerraScan software by Terrasolid Limited of Helsinki, Finland. In the filtering process points are classified as Ground or one of several non-Ground classes including Unclassified, Overlap, and Low Points.
    • Reclassification of Water Points: LiDAR returns from open water surfaces are commonly included in the Ground class by the ground filtering algorithms. Using 2D and 3D visualization methods, 2D vector polygons were digitized for significant waterways and water bodies that were readily identifiable in the LiDAR data. These polygons were then used to re-classify points in open water from the filtered Ground class to the Water class.
    • Coordinate Reprojection: Output LAS Files LIDAR points maintained in UTM coordinate system converted to Geographic projection with units of Decimal Degrees
    • The NOAA Coastal Services Center (CSC) received files in LAS format. The files contained LiDAR intensity and elevation measurements. CSC performed the following processing on the data to make it available within the LiDAR Data Retrieval Tool (LDART): 1. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03. 2. The LAS header fields were sorted by latitude and updated. 3. The data was filtered to eliminate outliers.
    • 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: 2013-06-07

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