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FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION TITLE: FLORIDA EXTENT (BY COUNTY) OF THE 100 METER, UNITED STATES NATIONAL GRID FOR NAD83 UTM ZONE 17N. Geodataset Name: USNG_FL_CNTY17_100M Geodataset Type: SHAPEFILE Geodataset Feature: Polygon Feature Count: 199900 |
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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 DATE OF AUTOMATION OF SOURCE: 20070426 GEODATASET EXTENT: Individual Florida Counties within UTM Zone 17 North |
FEATURE ATTRIBUTE TABLES:
Datafile Name: USNG_FL_CNTY17_100M.DBF
| ITEM NAME | WIDTH | TYPE | N. DECIMAL DEGREES |
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FID
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4 | OID | --- |
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Shape
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0 | Geometry | --- |
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X_LWRLFT
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19 | Number | 11 |
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Y_LWRLFT
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19 | Number | 11 |
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GRID100K
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2 | String | --- |
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GRID10K
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3 | String | --- |
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GRID1000M
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5 | String | --- |
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GRID100M
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7 | String | --- |
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LABEL
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10 | String | --- |
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DESCRIPT
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10 | String | --- |
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FGDLAQDATE
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8 | Date | --- |
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AUTOID
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9 | Number | --- |
FEATURE ATTRIBUTE TABLES CODES AND VALUES:
| Item | Item Description | |
| FID |
Internal feature number. |
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| Shape |
Feature geometry. |
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| X_LWRLFT |
X coordinate of the lower left hand corner of the polygon. |
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| Y_LWRLFT |
Y coordinate of the lower left hand corner of the polygon. |
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| GRID100K |
100,000-meter Square Identification; for regional areas, identified by two letter values. |
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| GRID10K |
10,000-meter grid label for the local area. |
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| GRID1000M |
1,000-meter grid label for the local area. |
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| GRID100M |
100-meter grid label for the local area. |
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| LABEL |
Concatenated 100K grid label and 100 meter grid label. |
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| DESCRIPT |
Based on LABEL. |
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| FGDLAQDATE |
The date FGDL acquired the data from the source. |
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| AUTOID |
GeoPlan internal feature identification number. |
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. |
How to Read a United States National Grid (USNG) Spatial Address http://www.fgdc.gov/usng/how-to-read-usng/index_html --------------------------------------------------------------- The USNG is an alpha-numeric reference system that overlays the UTM coordinate system. A USNG spatial address is broken down into three parts, the; - Grid Zone Designation; for a world-wide unique address. - 100,000-meter Square Identification; for regional areas. - Grid Coordinates; for local areas. 4 digits - 2306 - locates a point with a precision of 1,000-meters (a neighborhood size area). 6 digits - 234064 - locates a point with a precision of 100-meters (a soccer field size area). 8 digits - 23480647 - locates a point with a precision of 10-meters (the size of a modest home). 10 digits - 2348306479 - locates a point with a precision of 1-meter (within a parking spot). To review, we can see a complete US National Grid spatial address contains three parts as we drill down to a unique location, 18S UJ 23480647 - Grid Zone Designation (i.e. 18S). - 100,000-meter Square Identification (i.e. UJ ). - Grid coordinates of some even number of digits ranging from 2 to 10 (i.e. 23480647 In this case, eight digits identify a place of about the size of a modest home.). You always read right, then up when plotting coordinates. A spatial address is customarily written as a single string of values. Note how the horizontal datum (NAD 83) has been included: USNG: 18SUJ23480647 (NAD 83) Floridadisaster.org --------------------------------------------------------------- In an effort to standardize maps in Florida for both emergency and other operations, the State Fire Marshal, as the coordinating agency for search and rescue under the State Comprehensive Emergency Management Plan, and the Division of Emergency Management are embarking on a program to adopt the US National Grid (USNG) as the standard in Florida. This project will ensure a uniform grid mapping system across cities and counties in Florida, and will match the system used by the National Guard, the US Coast Guard and the US military when they are deployed into our state. Florida s unique geography of miles of coastlines, multiple river corridors, and large watersheds make the use of the common Township/Range/Section grid (PLSS) all but impossible except for a handful of inland counties. As the grid approaches wetlands, river corridors and the coast line, sections become irregular in shape and can be significantly larger than the typical square mile, which is too large to accommodate the needs of ground crews. Adoption of a national grid system has been identified as critical in a number of after action reports, investigations and studies dating as far back as Hurricane Andrew. FEMA, DHS, the National GeoSpatial Intelligence Agency, and the Federal Geographic Data Committee all promote the adoption of the USNG. Grid cell values are unique and sequentially numbered. |
The grid serves as a common means for providing locational information in relation to USNG coordinates. |
The grid's horizontal accuracy was mathematically generated and is accurate to the internal precision of ArcGIS 9.2 coordinates. |
The grid's vertical accuracy was mathematically generated and is accurate to the internal precision of ArcGIS 9.2 coordinates. |
THE DATA INCLUDED IN FGDL ARE 'AS IS' AND SHOULD NOT BE CONSTRUED AS LEGALLY BINDING. 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 |
Florida State Emergency Response Team United States National Grid http://floridadisaster.org/gis/usng/ Guidelines for Building US National Grid Polygons with ArcGIS http://floridadisaster.org/gis/usng/Documents/build_usng_polygons.pdf |
The University of Florida GeoPlan Center produced this grid in an ArcMap data viewer with the coordinate system set to NAD_83_UTM_Zone_17N. A 100-meter by 100 grid was generated, using the XTools Fishnet function covering the area of this specific county contained within the UTM 17 N zone. Some overlap was included for each county. Next the XTools Add XY function was used to produce X and Y coordinates for each polygon. Added fields: X_LWRLFT, Y_LWRLFT, GRID100K, GRID10K, GRID1000M, GRID100M, LABEL, DESCRIPT, FGDLAQDATE, and AUTOID. Calculate X_LWRLFT and Y_LWRLFT values as follows; Round ( [XCOORD] - 50, 0 ) Round ( [YCOORD] - 50, 0 ) After these calculations, the XCOORD and YCOORD fields may be deleted. Calculate GRID100K as follows; Using Select by Location function, selected features from the 100M grid that had their centroids within the selected usng_fl_100k.shp feature and then calculated the GRID100K field based on that selected usng_fl_100k.shp features value. Calculate GRID10K as follows; Mid ( [X_LWRLFT] , 2, 1 ) + " " + Mid ( [Y_LWRLFT] , 3 ,1 ) Calculate GRID1000M as follows; Mid ( [X_LWRLFT] , 2, 2 ) + " " + Mid ( [Y_LWRLFT] , 3 ,2 ) Calculate GRID100M as follows; Mid ( [X_LWRLFT] , 2, 3 ) + " " + Mid ( [Y_LWRLFT] , 3 ,3 ) Calculate LABEL as follows; [GRID100K] + " " + Mid ( [X_LWRLFT] , 2, 3 ) + Mid ( [Y_LWRLFT] , 3 ,3 ) Calculated DESCRIPT based on LABEL. Calculated the AUTOID field as follows; [FID] + 1 For more information on field calculations please see Guidelines for Building US National Grid Polygons with ArcGIS http://floridadisaster.org/gis/usng/Documents/build_usng_polygons.pdf Process Date: 20070426 |
Projection Transverse Mercator - UTM Zone 17N Datum NAD83 Units METERS Spheroid GRS1980 Scale Factor 0.9996 Central Meridian -81 00 0.000 Latitude of Origin 00 0 0.000 False Easting (meters) 500000.00000 False Northing (meters) 0.00000
DATA SOURCE CONTACT (S):
Name:
Abbr. Name:
Address:
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University of Florida GeoPlan Center GeoPlan 431 ARCH BLDG Gainesville, FL 32611 |
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