Lidar generated 2-foot contours for North Florida.
Contours consistent with the deliverables and including a certain level of smoothing. Index, Intermediate, Depression, Supplementary and Low confidence contours are coded.
A complete description of this dataset is available in the Minimum Technical Standard ( MTS report) "Final Report OF Specific Purpose LiDAR Survey - LiDAR-Generated Breaklines and Contours" submited to Florida Division of Emergency Management.
publication date
This data is for planning purposes only and should not be used for legal or cadastral purposes. Regional Evacuation Studies are currently being updated and www.floridadisaster.org/gis should be consulted for revisions.
2555 Shumard Oak Boulevard
GeoPlan relied on the integrity of the attribute information within the original data.
Data covers the tile scheme provided for the county and was verified for correct topology (no intersection, overlap or dangles). Dewberry performed a full qualitative review of the contour data for smoothness and consistency of feature codes.
A visual qualitative assessment was performed to ensure the data completness. No void or missing data except for the west end of the Santa Rosa island (missing Lidar data in existing dataset); concern FDEM tiles 051347_N, 051348_N, 051349_N.
The contours inherit the accuracy of the Lidar dataset it was acquired from. Lidar source compiled to meet 1m horizontal accuracy.
The contours inherit the accuracy of the Lidar dataset it was acquired from.
Based on the vertical accuracy testing conducted by Dewberry, using NSSDA and FEMA guidelines, vertical accuracy at the 95% confidence level (called Accuracyz) is computed by the formula RMSEz x 1.9600. The dataset for Escambia County, Florida satisfies the criteria: Countywide lidar dataset tested 13.7 cm vertical accuracy at 95% confidence level in open terrain, based on open terrain RMSEz (7 cm) x 1.9600. Countywide lidar dataset tested 33.3 cm vertical accuracy at 95% confidence level in all land cover categories combined, based on consolidated RMSEz (17 cm) x 1.9600.
Spatial and Attribute Information
The ABGPS, IMU, and raw scans are integrated using proprietary software developed by the Leica Geosystems and delivered with the Leica ALS50 System. The resultant file is in a LAS binary file format . The LAS file version 1.0 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 UTM Zone 16, with units in meters and 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.
501 Robert Blvd.
2nd Floor
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 1.0 format. The header file for each dataset is complete as define by the LAS 1.0 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
501 Robert Blvd.
2nd Floor
Conversion from UTM coordinates (meters) NAD83 into State Plane coordinates (U.S. Survey Feet) NAD83 HARN and conversion from ellipsoid heights (meters) into orthometric heights (U.S. Survey Feet).
200 Orchard Ridge Drive, Suite 101
Dewberry used GeoCue software to develop LiDAR stereo models. The raster resolution was 8ft.
8401 Arlington Boulevard
LiDAR intensity stereopairs were viewed in 3-D stereo using Socet Set softcopy photogrammetric software, the breaklines were stereo-compiled in accordance with the Data Dictionary. The LiDARgrammetry was performed under the direct supervision of an ASPRS Certified Photogrammetrist. The breaklines conform with data format requirements outlined by the FDEM Baseline Specifications.
8401 Arlington Boulevard
Using proprietary procedures developed by Dewberry using ArcGIS, a hydroenforced bare earth TIN was created. The nodes were gridded ground masspoints derived from the Lidar dataset, the 3D breaklines were included in this TIN.
1ft contours were modeled from a hydroenforced bare earth TIN and then smoothed and simplified using proprietary procedures developed by Dewberry using ArcGIS.
2ft contours were extracted from the 1ft contours dataset and suplemental contours were manually added from the 1ft contours dataset when needed.
GeoPlan received this data via hard drive from Jones Edmunds on 8/27/09 and on 5/5/10. When received the data was in multiple file geodatabases. The feature classes were projected to Albers HPGN. For the vendors other than pds, GeoPlan merged the data then clipped by county. For PDS the data was not merged and clipped. Therefore, the contours don't follow county boundaries exactly, but generally the edge of the contours are very close to the county boundary. PDS data had contours with 1 foot intervals in the 2 foot contour feature class. The following selection was performed on each county and the odd contours were deleted from the feature class using and edit session with ArcMap: MOD( "CONTOUR_ELEVATION_MS" , 2 ) = 1 The following counties had the associated amount of odd contours deleted: bay - 3259 brevard - 84 clay - 16 dixie - 10810 escambia - 34 flagler - 33249 franklin - 2298 gulf - 28084 jefferson - 2272 levy - 6791 nassau - 38 okaloosa - 107 putnam - 47 santa rosa - 2356 taylor - 6009 wakulla - 100 walton - 7884 -Added SOURCE field and populated all values to PDS -Added FGDLAQDATE field based on date GeoPlan acquired data from source -Changed name to TOPO2FT_PDS_COUNTY
Metadata imported.
Internal feature number.
ESRI
Feature geometry.
ESRI
Elevation of represented contour in feet
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Type of contour
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
INTERMEDIATE contours (the three or four lines between adjacent index contours) are about half the line weight of index contours. They are normally continuous throughout a map, but may be dropped or joined with an index contour where the slope is steep and where there is insufficient space to show all of the intermediate lines.
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
SUPPLEMENTARY contours are used to portray important relief features that would otherwise not be shown by the index and intermediate contours (basic contours). They are normally added only in areas of low relief, but they may also be used in rugged terrain to emphasize features. Supplementary contours are shown as screened lines so that they are distinguishable from the basic contours, yet not unduly prominent on the published map.
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
DEPRESSION contours are closed contours that surround a basin or sink. They are shown by right-angle ticks placed on the contour lines, pointed inward (down slope). Fill contours are a special type of depression contours, used to indicate an area that has been filled to support a road or railway grade.
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
INDEX contours are defined as every 5th contour line. For example, with the Contour_2FT feature class, the first positive intermediate contour would be 0 with the following index contours at 10, 20, 30 feet, etc.
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Intermediate Low Confidence
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Supplementary Low Confidence
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Depression Low Confidence
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Index Low Confidence
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
The date the feature was imported into the geodatabase
"Florida GIS - Baseline Specifications for Orthophotography and LiDAR v1.2"
Length of feature in internal units.
ESRI
Abbreviated 3-letter code representing the data source.
GeoPlan
PDS
Date FGDL acquired data from source
GeoPlan
431 Architecture PO Box 115706
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
2555 Shumard Oak Boulevard