2005 Southwest Florida Water Management District (SWFWMD) LiDAR: Weeki Wachee
This kmz file shows the extent of coverage for the 2005 SWFWMD Weeki Wachee, FL lidar
This data set is one component of a digital terrain model (DTM) for Weeki Wachee,
Hernando County, Florida encompassing approximately 13.5 square miles. This dataset
is comprised of 15 LiDAR files, based on the DISTRICT 5,000' by 5,000' sheet index
system, in the LAS file format. The raw data was collected at an average ground sample
distance of 1-meter. Other components of the DTM include: 3-D breaklines along hydrographic
features in the Shape file format; lake/pond polygons (in 3D) in the shape file format;
obscured area polygons (in 2D) in the Shape file format; and hard/soft breaklines
(in 3D) in the Shape file format.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
||Southwest Florida Water Management District
Documentation links not available.
- Southwest Florida Water Management District (SWFWMD)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||The DTM was developed to support the DISTRICT's regulatory, land management and acquisition,
planning, engineering, and habitat restoration projects
|| Unknown to Unknown
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- LiDAR LAS digital terrain model
- Weeki Wachee
- Gulf Coast
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
| Processing Steps
- The LiDAR data was acquired using a Leica ALS50 from an altitude of 1,000-meters above
ground level to provide an average ground sample distance of 1-meter. The scanner
field of view was 44-degrees, and the scan rate was 33-hertz. First and last return
data was collected along with the signal return intensity. 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
4 classifications: 1 = unclassified; 2 = ground; 9 = water; and 10 = photogrammetric
mass points. The class 1 consists of all points not on the ground. Class 2 consists
of bare earth points. Class 3 consists of points within water polygons such as swamps
and/or wetlands. Class 4 consists of supplementary mass points that were photogrametrically
compiled on points features suchs as peaks or pits, and they were created to mainatin
the accuracy of the DTM.
- The NOAA Coastal Services Center (CSC) received the files in las format. The files
contained lidar elevation and intensity measurements. The data were in FL State Plane
West coordinates and NAVD88 (orthometric) heights in feet. CSC performed the following
processing for data storage and Digital Coast provisioning purposes: 1. The data were
converted from FL State Plane west coordinates to geographic coordinates. 2. The data
were converted from NAVD88 (orthometric) heights in feet to GRS80 (ellipsoid) heights
in meters using Geoid 03. 3. The LAS data were sorted by latitude and the headers
were updated. 4. The data were converted to LAZ format.
- 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
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
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
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: 2013-10-17
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