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2006 Southwest Florida Water Management District (SWFWMD) Lidar: North District

This data set is one component of a digital terrain model (DTM) for the Southwest Florida Water Management District's FY2006 Digital Orthophoto (B089) and LiDAR Project (L470/L471), encompassing approximately 1,216 square miles across Citrus and Sumter counties. The 2006 LiDAR dataset is comprised of 3-D masspoints delivered in the LAS file format based on the District's 5,000' by 5,000' grid (1,356 cells). The other DTM component is 2-D and 3-D breakline features in the ESRI ArcGIS Personal Geodatabase format. In accordance with the 2006 SWFWMD Topographic Database Design, the following breakline features are contained within the database: closed water bodies (lakes, reservoirs, etc) as 3-D polygons; linear hydrographic features (streams, canals, swales, embankments, etc) as 3-D breaklines; coastal shorelines as 3-D linear features; edge of pavement road features as 3-D breakines; soft features (ridges, valleys, etc.) as 3-D breaklines; obscured vegetation polygons as 2-D polygons; overpasses and bridges as 3-D breaklines; 1-foot contours for visualization purposes; and island features as 3-D polygons. This data falls in Citrus and Sumter Counties. Intensity values, or the measure of reflectance of the laser are also captured. Breakline features were captured to develop a hydrologically correct DTM. Contours (1-foot) were generated from the DTM that meet the National Map Accuracy Standards for 2-foot contours (FEMA specifications). Bare earth LiDAR masspoint data display a vertical accuracy of at least 0.3-feet root mean square error (RMSE) in open unobscured areas

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor Distributor information not available
    Point of Contact Mapping and GIS Section
    Southwest Florida Water Management District
    Documentation links not available.
    • Southwest Florida Water Management District (SWFWMD)
      • publication: 2007-01-05
      Data Presentation Form: Digital image
      Dataset Progress Status Complete
      Data Update Frequency: As needed
      Supplemental Information: Project Title: FY2006 Digital Orthophoto (B089) and LiDAR Project (L470/L471) Purchase Order: 06PCSOW0471 Work Order Name: North District Ortho and LiDAR - Work Order 1 Vendor Name: Woolpert, Inc
      Purpose: The DTM was developed to support the DISTRICT's regulatory, land management and acquisition, planning, engineering, and habitat restoration projects
      Time Period: Unknown  to  Unknown
      Spatial Reference System:
      Spatial Bounding Box Coordinates:
      N: 29.06432
      S: 28.29512
      E: -81.94110
      W: -82.73904
      Spatial Coverage Map:
      • Topography/Bathymetry
      • laser
      • Terrain
      • Model
      • Elevation
      • Surface
      • LiDAR
      • United States
      • Florida
      • Citrus County
      • Sumter County
      Use Constraints No constraint information available
      Fees Fee information not available.
      Lineage Statement Lineage statement not available.
      • Woolpert, Inc.
      • DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department of Commerce
      Processing Steps
      • The LiDAR data was acquired using a Leica ALS50 from an altitude of 2,400' above ground level to provide an nominal ground sample distance of 2.4-feet. The scanner field of view was 28-degrees, and the scan rate was 46-hertz. First and last return data was collected along with the signal return intensity. A total of 278 flights of LiDAR data were acquired. Flight lines were flown with a 30% sidelap, providing a line-to-line swath width of 957-feet. Thirty (30) Two redundant airborne GPS bases stations were utilized during the data acquisition with maximum line-of-sight distance between the base station and aircraft of 20-km. The LiDAR data was reduced using Grafnav (Waypoint Consulting) for GPS post-processing, PosProc (Applanix Crop) for IMU processing, ALS50 Post Processor (LH Systems) to initial LiDAR processing, TerraScan (Terrasolid) for initial point classification, and proprietary Woolpert developed software for refining the point classification and QC. The LAS files contain 5 classifications: 1 = unclassified; 2 = ground; 9 = water; and 10 = photogrammetric mass points and 11=swamp/wetland points. The class 1 consists of all points not on the ground. Class 2 consists of bare earth points. Class 9 points are those points falling within lake/pond polygons. Class 10 consists of supplementary mass points that were photogrametrically compiled on points features suchs as peaks or pits, and they were created to maintain the accuracy of the DTM. Class 11 consists of points within swamps and/or wetlands polygons classified as ground. For a complete description of survey methods, processing methods, software, system parameters, and accuracy analysis, see the Florida MTS Report of Specific Purpose Survey, North District LiDAR DTM Project (L470/L471), dated January 2007.
      • The NOAA Coastal Services Center (CSC) received the the files in LAS format. The files contained Lidar elevation measurements. The data was in Florida State Plane Projection and NAVD88 vertical datum. CSC performed the following processing to the data to make it available within the LDART Retrieval Tool (LDART): 1. The data were converted from Florida State Plane West coordinates to geographic coordinates. 2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid03. 3. 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 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 ( 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: 2013-06-11

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