2009 St. Johns River Water Management District (SJRWMD) Lidar: Portions of Orange
and Seminole Counties, Florida
This kmz file shows the extent of coverage for the 2009 SJRWMD Seminole and Orange
counties lidar data set.
The project area covers 318 square miles in the eastern half of Seminole County plus
portions of north central and northeast Orange County in the state of Florida. The
LiDAR data was collected 8 - 11 February 2009. The data are classified: 1 = Unclassified,
2 = Ground, 7 = Noise, 9 = Water and 12 = Overlap.
Cite this dataset when used as a source.
|Search and Download
|| Distributor information not available
| Point of Contact
||St. Johns River Water Management District
- St. Johns River Water Management District (SJRWMD)
|Data Presentation Form:
|| Digital image
|Dataset Progress Status
|Data Update Frequency:
|| As needed
||To develop a consistent and accurate surface elevation dataset for a portion of the
Central Florida Coordination Area (CFCA) in accordance with the Florida Department
of Emergency Management (FDEM) Baseline Specifications. The CFCA defines an area that
faces particularly difficult water supply issues. Three of Florida's Water Management
Districts have jurisdiction in the CFCA: the South Florida Water Management District
(SFWMD), the St. Johns River Water Management District (SJRWMD), and the Southwest
Florida Water Management District (SWFWMD). These three water management districts
are cooperating to develop and implement mutually acceptable strategies to provide
adequate supplies of water to support projected growth without unacceptable impacts.
||2009-02-08 to 2009-02-11
|Spatial Reference System:
|Spatial Bounding Box Coordinates:
|Spatial Coverage Map:
- United States
- Orange County
- Seminole County
| Use Constraints
|| No constraint information available
|| Fee information not available.
|| Lineage statement not available.
- Merrick & Co
- Merrick & Co
- Merrick & Co
- DOC/NOAA/NESDIS/NGDC > National Geophysical Data Center, NESDIS, NOAA, U.S. Department
| Processing Steps
- The ABGPS, IMU, and raw Leica ALS50 LiDAR data are integrated with Leica's Incorporated's
ALS Post Processor software. The resultant file is in a LAS binary file format. The
LAS file version 1.1 format 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 HARN horizontal datum and NAVD88 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 defined by the LAS 1.1 specification. In addition the following fields
are included: Flight Date Julian, Year, and Class. The data was classified as follows:
Class 1 = Unclassified. This class includes vegetation, buildings, noise etc. Class
2 = Ground Class 7 = Noise Class 9 = Water Class 12 = Overlap
- Ground points were extracted from the Lidar dataset, class 2, and converted to a multipoint
feature class using ArcGIS.
- 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 Digital Coast: 1. The data were converted
from UTM Zone 17 coordinates to geographic coordinates. 2. The data were converted
from NAVD88 heights to ellipsoid heights using Geoid03. 3. The LAS header fields were
sorted by latitude and updated. 4. The data were filtered to remove 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: 2013-06-04
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