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FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION TITLE: FLORIDA DIGITAL ELEVATION MODEL (DEM) MOSAIC - 5-METER CELL SIZE - ELEVATION UNITS CENTIMETERS Geodataset Name: FLIDAR_MOSAIC_CM Geodataset Type: RASTER Geodataset Feature: 5-METER CELL Feature Count: 4154 |
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GENERAL DESCRIPTION:
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DATA SOURCE(S): University of Florida GeoPlan Center SCALE OF ORIGINAL SOURCE MAPS: N/A GEODATASET EXTENT: State of Florida |
FEATURE ATTRIBUTE TABLES:
Datafile Name: FLIDAR_MOSAIC_CM
| ITEM NAME | WIDTH | TYPE |
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OBJECTID
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4 | OID |
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Value
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4 | Integer |
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Count
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8 | Double |
FEATURE ATTRIBUTE TABLES CODES AND VALUES:
| Item | Item Description | |
| OBJECTID |
Internal feature number. |
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| Value |
Elevation in centimeters. |
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| Count |
Count of cells with the same elevation value. |
This data is provided 'as is'. GeoPlan relied on the integrity of the original data layer's topology |
This data is provided 'as is' by GeoPlan and is complete to our knowledge. |
GeoPlan relied on the integrity of the attribute information within the original data. |
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The data was created to serve as base information for use in GIS systems for a variety of planning and analytical purposes. |
This data is provided 'as is' and its horizontal positional accuracy has not been verified by GeoPlan |
This data is provided 'as is' and its vertical positional accuracy has not been verified by GeoPlan |
None |
The Florida Geographic Data Library is a collection of Geospatial Data compiled by the University of Florida GeoPlan Center with support from the Florida Department of Transportation. GIS data available in FGDL is collected from various state, federal, and other agencies (data sources) who are data stewards, producers, or publishers. The data available in FGDL may not be the most current version of the data offered by the data source. University of Florida GeoPlan Center makes no guarantees about the currentness of the data and suggests that data users check with the data source to see if more recent versions of the data exist. Furthermore, the GIS data available in the FGDL are provided 'as is'. The University of Florida GeoPlan Center makes no warranties, guaranties or representations as to the truth, accuracy or completeness of the data provided by the data sources. The University of Florida GeoPlan Center makes no representations or warranties about the quality or suitability of the materials, either expressly or implied, including but not limited to any implied warranties of merchantability, fitness for a particular purpose, or non-infringement. The University of Florida GeoPlan Center shall not be liable for any damages suffered as a result of using, modifying, contributing or distributing the materials. A note about data scale: Scale is an important factor in data usage. Certain scale datasets are not suitable for some project, analysis, or modeling purposes. Please be sure you are using the best available data. 1:24000 scale datasets are recommended for projects that are at the county level. 1:24000 data should NOT be used for high accuracy base mapping such as property parcel boundaries. 1:100000 scale datasets are recommended for projects that are at the multi-county or regional level. 1:125000 scale datasets are recommended for projects that are at the regional or state level or larger. Vector datasets with no defined scale or accuracy should be considered suspect. Make sure you are familiar with your data before using it for projects or analysis. Every effort has been made to supply the user with data documentation. For additional information, see the References section and the Data Source Contact section of this documentation. For more information regarding scale and accuracy, see our webpage at: http://geoplan.ufl.edu/education.html |
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The following source DEMs were used to create a statewide DEM. The sources are
listed in order of priority:
1) Northwest Florida Water Management District (NWFWMD) DEM
description: Received from NWFWMD district in 2012. This DEM was created
from a variety of different sources, metadata from each source used by
NWFWMD is included with the FGDL download and is located in the following
folder: ...\meta\nwfwmd
cell size: 2, 2 (meters)
pixel type: floating point
elevation units: feet
elevation datum: NAVD88
2) NOAA FLIDAR Coastal DEM
description: This DEM is based on coastal Lidar data sourced from the NOAA
Coastal Services Center. Metadata from each source used by NOAA is included
with the FGDL download and is located in the following folder: ...\meta\noaa
cell size: 5.4329891, 5.4329891 (meters)
pixel type: unsigned integer
elevation units: inches
elevation datum: NAVD88
3) Florida Fish and Wildlife Conservation Commission (FWC) Florida Statewide 5-Meter DEM
description: this is a statewide DEM that has some gaps. The DEM was
received from FWC in 2012. Note: the source vertical datum was NGVD29,
which was converted to NAVD88. Original metadata for this source DEM is
included with the FGDL download and is located in the following folder:
...\meta\fwc
cell size: 5.4329891, 5.4329891 (meters)
pixel type: floating point
elevation units: meters
elevation datum: NGVD29
4) Contour Derived DEM
description: This DEM is based on 2ft contours from the coastal LiDAR
project. The biggest portion of this source data is around Lake Okeechobee,
where data was from Merrick. For more information on the contour data please
see FGDL layers prefixed with "TOPO2FT_".
cell size: 5.4329891, 5.4329891 (meters)
pixel type: unsigned integer
elevation units: inches
elevation datum: NAVD88
=============================================================================
Processing steps for statewide DEM: 20121018
Using ArcGIS 10.0, the following process was executed to create the statewide
DEM.
During any command that was executed the following environment settings were used:
set snap raster as NOAA FLIDAR Coastal DEM
set cell size = NOAA FLIDAR Coastal DEM (5.4329891, 5.4329891)
-Copy Raster command was executed to resample NWFWMD District DEM from 2
meter cells to 5 meter cells. Converted raster from floating point to integer and
changed units to inches.
-Mosaic to New Raster command executed to combine the NWFWMD District
DEM and the FLIDAR Coastal DEM. The NWFWMD District DEM was given
priority.
-Used Raster Calculator to convert the FWC DEM to integer and used the
following formula (("fwc_mos88" * 39.3696) + 0.5) to convert to inches
(please note: the 0.5 was added to account for ArcMaps rounding rules)
-Mosaic to New Raster command executed to combine the previous mosaic with
processed FWC DEM. Priority was given to the mosaic.
-Used Contour to DEM tool to create a DEM of the area where gaps existed.
The 2ft contours from the coastal LiDAR project were used.
-Mosaic to New Raster command executed to combine previous mosaic with
contour derived DEM, priority was given to previous mosaic.
-Set all negative (-302 to -1) values to null
-Created a water grid using water areas from 5 Water Management District Landuse/Landcover layers where:
- LEVEL1='WATER'
- SFWMD where FLUCCS = 1660 (HOLDING PONDS)
- SRWMD where FLUCCS = 8160 (CANALS AND LOCKS)
- NWFWMD where FLUCCS = 8160 (CANALS AND LOCKS)
-Reclassed all water grid values to -1
-Mosaic to New Raster command executed to combine the water grid and previous mosaic.
-The final output raster feature class was named flidar_mosaic_in and was
copied into a 9.3.1 file geodatabase with the following properties:
pixel units: inches
single band
16bit signed integer
cell size: 5.4329891, 5.4329891 meters
projection: Albers HPGN
vertical datum: NAVD88
-The final product (flidar_mosaic_in) was converted to feet, centimeters, and meters
and named flidar_mosaic_ft, flidar_mosaic_cm, flidar_mosaic_m
Notes:
-The Northwest Florida Water Management District DEM was considered the
highest order data source based on a nominal 2-meter horizontal resolution, which
is closer to the native resolution of the original coastal Lidar data collection
than all other sources used in this mosaic. Vertical values for the NWFWMD DEM
are recorded in feet, while the vertical accuracy for the original Lidar data
collection is reported in inches. Therefore, the decision was made to
standardize all data sets and construct the mosaic with inches as the vertical
unit.
-No smoothing was done when executing mosaic commands. In some areas where
DEMs come together there are discrepancies, typically these differences are
minimal and can't be seen at all when zooming out beyond 1:240K.
-A feature class representing the source data used for the DEM can be found in
the same file geodatabase as the DEM and called flidar_mosaic_source.
-The processing for this data was done primarily using ArcGIS Desktop 10.0, all
data is delivered in a 9.3.1 compliant File GeoDatabase.
Process Date: 201021018
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Projection ALBERS Datum HPGN Units METERS Spheroid GRS1980 1st Standard Parallel 24 0 0.000 2nd Standard Parallel 31 30 0.000 Central Meridian -84 00 0.000 Latitude of Projection's Origin 24 0 0.000 False Easting (meters) 400000.00000 False Northing (meters) 0.00000
DATA SOURCE CONTACT (S):
Name:
Abbr. Name:
Address:
Phone:
Web site:
E-mail:
Contact Person:
Phone:
E-mail:
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University of Florida GeoPlan Center GeoPlan 431 Architecture Building Gainesville, FL 32611 n/a |
Name: FLORIDA GEOGRAPHIC DATA LIBRARY
Abbr. Name: FGDL
Address: Florida Geographic Data Library
431 Architecture Building
PO Box 115706
Gainesville, FL 32611-5706
Web site: http://www.fgdl.org
Contact FGDL:
Technical Support: http://www.fgdl.org/fgdlfeed.html
FGDL Frequently Asked Questions: http://www.fgdl.org/fgdlfaq.html
FGDL Mailing Lists: http://www.fgdl.org/fgdl-l.html
For FGDL Software: http://www.fgdl.org/software.html