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2004 St. Johns County, Florida Lidar

This dataset is the bare earth lidar data for St. Johns County, Florida, acquired in early January and February of 2004. This data was collected to develop comprehensive countywide base mapping and perform other GIS enhancements to support master drainage planning, transportation planning, preliminary engineering and wetland preservation studies. The surveyed area included all of St. Johns County, approximately 610 square miles. Eighty-seven (87) flight lines of high density lidar data (average GSD is 3.3 feet) were obtained at an altitude of 3000 feet AGL. This data set contains only model keypoints (points that are a thinned data set that is intended to remove extraneous data such as trees and points that are deemed redundant to the final bare earth product) that are classified as ground points. As a result, there are a lower number of points than in a full mass point lidar data set; and it is recommended that the data be downloaded as points and used with a TIN (Triangulated Irregular Network) or similar algorithm to produce a bare earth surface.

Cite this dataset when used as a source.

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    Distribution Formats
    • LAZ
    Distributor Distributor information not available
    Point of Contact Mike Campbell
    St. Johns County Florida GIS
    Associated Resources
    • Lidar Final Report
    • St. Johns County, Florida Public Works Department
      • publication: 2004-01-01
      Data Presentation Form: Digital image
      Dataset Progress Status Complete
      Data Update Frequency: As needed
      Purpose: The purpose of this topographic lidar survey was to produce a digital terrain model (DTM) of sufficient density and accuracy to generate 1-foot contours, compile limited planimetric features and generate panchromatic (black and white) digital orthophoto imagery (DOI).
      Time Period: 2004-01-17  to  2004-02-07
      Spatial Reference System:
      Spatial Bounding Box Coordinates:
      N: 30.259696
      S: 29.621896
      E: -81.212673
      W: -81.669173
      Spatial Coverage Map:
      • Bathymetry/Topography
      • LiDAR
      • Terrain
      • Model
      • Elevation
      • Surface
      • Laser
      • US
      • Florida
      • St. Johns 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 in 93 flight lines acquired in 6 sessions between January 17 and February 7, 2004 from an altitude of 3,000 feet above ground level (AGL) to provide an average ground sample distance (GSD) of 3.3 feet. Three concurrent airborne GPS base stations were used for each acquisition session. The ABGPS data were reduced using the GrafNav software package by Waypoint Consulting, Inc. The IMU data was reduced using the PosProc software package by Applanix Corporation. The initial lidar "point cloud" was derived through the ALS Post Processor software package by Leica Geosystems. The aircraft, lidar system and associated computer hardware and software are owned and operated by Woolpert LLP. Once the initial lidar "point cloud" was derived, Woolpert performed QC to look for any systematic error within the lidar flights using proprietary software. After systematic error was identified and removed, the individual lidar flights were clipped to remove overlap between adjacent flight lines and provide a homogeneous coverage over the project extents. Using the homogeneous coverage, above ground features were classified and removed using proprietary software to produce the bare-earth coverage.
      • The NOAA Coastal Services Center (CSC) received the files in ASCII format. The data was in Florida State Plane Projection, NAVD88 vertical datum and the vertical units of measure were feet. CSC performed the following processing to the data to make it available within Digital Coast: 1. The data were converted from Florida State Plane East, Zone 0901 coordinates to geographic coordinates. 2. The data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights using Geoid 03. 3. The vertical unit of measure for the data was converted from feet to meters. 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 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: 2013-05-07

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