2008 NWFWMD (Northwest Florida Water Management District) Florida LiDAR: Inland Okaloosa
This Light Detection and Ranging (LiDAR) LAS dataset is a survey of inland Okaloosa
County, Florida not covered in the 2008 Florida Department of Emergency Management
LiDAR initiative. The project area consists of approximately 874 square miles, including
a buffer of approximately 50 feet along the edges of the project. The project design
of the LiDAR data acquisition was developed to support a nominal post spacing of 4.9
feet or 1.5 meters for un-obscured areas. Fugro EarthData, Inc. acquired 49 flight
lines in three lifts on February 10, 2008. The data was divided into 5000' by 5000'
foot cells that serve as the tiling scheme. LiDAR data collection was performed with
a Cessna 310 aircraft, utilizing a Leica ALS50-II MPiA sensor, collecting multiple
return x, y, and z data as well as intensity data. LiDAR data was processed to achieve
a bare ground surface. 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. This data of inland Okaloosa County, Florida, was collected
at sufficient resolution to provide a nominal point spacing of 1.5m 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.
|Search and Download
|| Distributor information not available
| Point of Contact
- Northwest Florida Water Management District (NWFWMD)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||The mission of the Coastal Services Center is to support the environmental, social,
and economic well being of the coast by linking people, information, and technology.
The mission of the Northwest Florida Water Management District (NWFWMD) is to protect
and manage the water resources of northwest Florida in a sustainable manner for the
continued welfare of its residents and natural systems. These LiDAR data are intended
to support the local Coastal Zone Managers in their decision-making processes. This
data will be used for flood plain mapping and other coastal management applications.
|| Unknown to Unknown
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- Bare Earth
- United States
- Okaloosa County
- Eglin AFB
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
- Fugro EarthData, Inc.
- Fugro EarthData, Inc.
- DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department
| Processing Steps
- EarthData International, Inc. collected ALS-50-derived LiDAR over Okaloosa County,
Florida with a 1.5m, nominal post spacing using a Cessna 310 aircraft. The collection
for the entire project area was accomplished in one day on February 10, 2008. The
collection was performed by EarthData International, Inc., using a Leica ALS50-II
MPiA LiDAR system, serial number ALS039, including an inertial measuring unit (IMU)
and a dual frequency GPS receiver. This project required 3 lifts of flight lines to
be collected. The lines were flown at an average of 6,000 feet above mean terrain
using a pulse rate of 122,500 pulses per second.
- The airborne GPS data were processed and integrated with the IMU. The results were
imported into the processing system for use in the LiDAR boresight. The raw LiDAR
data was downloaded onto a production server. The ground control and airport GPS base
station were used in conjunction with the processed ABGPS results for the LiDAR boresight.
The properly formatted processing results were used for subsequent processing.
- EarthData has developed a unique method for processing LiDAR data to identify and
remove elevation points falling on vegetation, buildings, and other aboveground structures.
The algorithms for filtering data were utilized within EarthData's proprietary software
and commercial software written by TerraSolid. This software suite of tools provides
efficient processing for small to large-scale, projects and has been incorporated
into ISO 9001 compliant production work flows. The following is a step-by-step breakdown
of the process. 1. Using the LiDAR data set provided by EarthData Aviation, the technician
performs calibrations on the data set. 2. The technician performed a visual inspection
of the data to verify that the flight lines overlap correctly. The technician also
verified that there were no voids, and that the data covered the project limits. The
technician then selected a series of areas from the data set and inspected them where
adjacent flight lines overlapped. These overlapping areas were merged and a process
which utilizes 3-D Analyst and EarthData's proprietary software was run to detect
and color code the differences in elevation values and profiles. The technician reviewed
these plots and located the areas that contained systematic errors or distortions
that were introduced by the LiDAR sensor. 3. Systematic distortions highlighted in
step 2 were removed and the data was re-inspected. Corrections and adjustments can
involve the application of angular deflection or compensation for curvature of the
ground surface that can be introduced by crossing from one type of land cover to another.
4. The LiDAR data for each flight line was trimmed in batch for the removal of the
overlap areas between flight lines. The data was checked against a control network
to ensure that vertical requirements were maintained. Conversion to the client-specified
datum and projections were then completed. The LiDAR flight line data sets were then
segmented into adjoining tiles for batch processing and data management. 5. The initial
batch-processing run removed 95% of points falling on vegetation. The algorithm also
removed the points that fell on the edge of hard features such as structures, elevated
roadways and bridges. 6. The operator interactively processed the data using LiDAR
editing tools. During this final phase the operator generated a TIN based on a desired
thematic layer to evaluate the automated classification performed in step 5. This
allowed the operator to quickly re-classify points from one layer to another and recreate
the TIN surface to see the effects of edits. Geo-referenced images were toggled on
or off to aid the operator in identifying problem areas. The data was also examined
with an automated profiling tool to aid the operator in the reclassification. 7. The
point cloud data were delivered in LAS 1.1 format. 9 - points in water, 2 - ground
points, and 1 - all other.
- The LiDAR ground points created in Process Step 3 were loaded into a Terrascan project.
The export lattice model function in Terrascan was then used to create and output
the LiDAR DEM grid to the Arc ASCII Raster format. As a final step, the Arc ASCII
Raster format grid tiles were converted to ESRI Grid format using an Arc command.
- 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 LAS files were converted from UTM coordinates to geographic coordinates. 2. The
data were converted from NAVD88 (orthometric) heights to GRS80 (ellipsoid) heights
using Geoid 03. 3. The LAS header fields were sorted by latitude and updated. 4. 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
Metadata Last Modified: 2013-06-05
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