2008 Northwest Florida Water Management District Lidar: Eglin Air Force Base, Walton
This kmz file shows the extent of coverage for the 2008 NWFWMD Walton County-Eglin
AFB lidar data set.
In the summer of 2008, the Northwest Florida Water Management District collected lidar
data over a portion of Walton County, FL (Eglin Air force Base) to support various
projects such as floodplain and hazards mapping, wetlands mitigation and stormwater
management. The data collection occured in a portion of the county for which there
is no prior collected lidar data. Used in conjunction with previously collected data
in Walton County (FDEM Lidar collected in 2006), these data support the creation of
a county-wide, high resolution, lidar derived digital elevation model(DEM).
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
||John B. Crowe
Northwest Florida Water Management District
Documentation links not available.
- Northwest Florida Water Management District (NWFWMD)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
||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 water, bare
ground or not bare ground to support creation of a bare earth model from the data.
||To supplement previously collected lidar data in the creation of county-wide, high
resolution, lidar derived digital elevation models (DEM).
|| Unknown to Unknown
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Digital Elevation Model
- Walton County
- Eglin Air Force Base
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
- Sanborn Map Company, Inc
- DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department
| Processing Steps
- The ABGPS, IMU, and raw Optech 3100 LiDAR data are integrated into the TerraScan 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 date and time
for each flight line can be determined using the Julian date and time. The Julian
date is a continuous count of days and fractions since noon Universal Time on January
1, 4713 BCE on the Julian calendar.
- 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 overlap.
The data was classified as follows: Class 1 = Unclassified. This class includes vegetation,
buildings, noise etc. Class 2 = Ground Class 9 = Water
- Conversion from Geodetic coordinates, NAD83 into State Plane coordinates (meters)
and conversion from ellipsoid heights (meters) into orthometric heights (U.S. Survey
- 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 for data storage purposes and Digital Coast provisioning: 1. The data
were converted from State Plane Florida West coordinates to geographic (NAD83) coordinates.;
2. the data were filtered to remove elevation outliers.; 3. The data were converted
from NAVD88 heights to ellipsoid heights using Geoid03.; 4. The LAS header fields
were sorted by latitude and 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
Metadata Last Modified: 2013-06-05
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