FLORIDA GEOGRAPHIC DATA LIBRARY DOCUMENTATION TITLE: HORIZONTAL AND VERTICAL GEODETIC CONTROL DATA FOR FLORIDA - MAY 2014 Geodataset Name: NGS_POINTS_MAY14 Geodataset Type: SHAPEFILE Geodataset Feature: Point Feature Count: 50640 |
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GENERAL DESCRIPTION:
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DATA SOURCE(S): National Oceanic and Atmospheric Administration, National Geodetic Survey SCALE OF ORIGINAL SOURCE MAPS: Unknown GEODATASET EXTENT: State of Florida |
FEATURE ATTRIBUTE TABLES:
Datafile Name: NGS_POINTS_MAY14.DBF
ITEM NAME | WIDTH | TYPE |
OBJECTID
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4 | OID |
Shape
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4 | Geometry |
FeatureId
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2 | SmallInteger |
DATA_DATE
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8 | String |
DATA_SRCE
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57 | String |
DEC_LONG
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15 | String |
DEC_LAT
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13 | String |
PID
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6 | String |
NAME
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40 | String |
STATE
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2 | String |
COUNTY
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26 | String |
QUAD
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40 | String |
LATITUDE
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17 | String |
LONGITUDE
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18 | String |
POS_DATUM
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6 | String |
DATUM_TAG
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6 | String |
POS_SRCE
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12 | String |
ELEVATION
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9 | String |
ELEV_DATUM
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12 | String |
ELEV_SRCE
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12 | String |
ELLIP_HT
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9 | String |
ELLIP_SRCE
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12 | String |
POS_ORDER
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1 | String |
POS_CHECK
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1 | String |
ELEV_ORDER
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1 | String |
ELEV_CLASS
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1 | String |
ELEV_CHECK
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1 | String |
DIST_RATE
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1 | String |
ELLP_ORDER
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1 | String |
ELLP_CLASS
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1 | String |
FIRST_RECV
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8 | String |
LAST_RECV
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8 | String |
LAST_COND
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16 | String |
LAST_RECBY
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6 | String |
SAT_USE
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1 | String |
SAT_DATE
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8 | String |
STABILITY
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1 | String |
DESCRIPT
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50 | String |
FGDLAQDATE
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36 | Date |
AUTOID
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4 | Integer |
FEATURE ATTRIBUTE TABLES CODES AND VALUES:
Item | Item Description | |
OBJECTID |
Internal feature number. |
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Shape |
Feature geometry. |
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FeatureId |
Temporary unique ID assigned to this station. |
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DATA_DATE |
The date when this information was retrieved from the NGS database. |
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DATA_SRCE |
Data Source where the information for the mark came from. You should use this link to obtain a full datasheet for the mark or obtain the datasheets from <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl> if you intend to use the data for survey control. |
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DEC_LONG |
Decimal equivalent of the LONGITUDE Always displayed to 10 decimal places, but you should see POS_SRCE and POS_ORDER to determine the true accuracy. |
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DEC_LAT |
Decimal equivalent of the LATITUDE |
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PID |
Permanent Identifier assigned by NGS to each mark |
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NAME |
Station Name (a.k.a. Designation) |
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STATE |
State Code |
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COUNTY |
County Name |
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QUAD |
USGS Topographic Quad Map Name |
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LATITUDE |
Latitude in Deg-Min-Sec format |
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LONGITUDE |
Longitude in Deg-Min-Sec format |
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POS_DATUM |
Datum of the LATITUDE,LONGITUDE Should always be NAD83 |
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DATUM_TAG |
Datum Tag of the LATITUDE,LONGITUDE NAD83 (1986) indicates positions on the NAD83 datum for the North American Adjustment, completed in 1986. NAD83 (nnnn) indicates positions on the NAD83 datum for the North American Adjustment, but readjusted to a State High Accuracy Reference Network (HARN) on the date shown in (nnnn). NAD83 (CORS) indicates positions which are part of the CORS network. |
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POS_SRCE |
Position Source for the LATITUDE,LONGITUDE
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ELEVATION |
Present if available. The Orthometric Height in METERS indicating the height above the Geoid. |
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ELEV_DATUM |
Datum of the ELEVATION |
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ELEV_SRCE |
Elevation Source for the ELEVATION
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ELLIP_HT |
Present if available. The ellipsoid height in METERS referenced to GRS80 ellipsoid. |
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ELLIP_SRCE |
Ellipsoid Ht Source for the ELLIP_HT Should always be GPS_OBS when present. |
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POS_ORDER |
Order of accuracy for the LATITUDE,LONGITUDE Should be one of the following- A,B,1,2,3 Order and class for Orders 1, 2, and 3 are defined in the Federal Geodetic Control Committee publication "Standards and Specifications for Geodetic Control Networks". In addition- Order A stations have a relative accuracy of 5 mm +/- 1-10,000,000 relative to other A-order stations. Order B stations have a relative accuracy of 8 mm +/- 1- 1,000,000 relative to other A- and B-order stations. |
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POS_CHECK |
Observational Check
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ELEV_ORDER |
Order of accuracy for the ELEVATION Should be 1,2, or 3 for Vertical Control Stations. Will be blank for stations used for Horizontal Control only. Also see attribute DIST_RATE which is used for some vertical control stations. Elevation order and class for 1, 2, and 3 are defined in the Federal Geodetic Control Committee publication "Standards and Specifications for Geodetic Control Networks". In addition- Vertical control which were determined only for the purpose of supplying a height for Horizontal Distance Reductions are assigned an order of 3. Class 0 is used for special cases of orthometric vertical control as follows-
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ELEV_CLASS |
Should be 0, 1, or 2 See details under ELEV_ORDER |
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ELEV_CHECK |
Observational Check
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DIST_RATE |
Distribution rate for POSTED and READJUSTED benchmarks which do not have an Order and Class are as follows "Posted bench marks" are vertical control points in the NGS data base which were excluded from the NAVD 88 general adjustment. Some of the bench marks were excluded due to large adjustment residuals, possibly caused by vertical movement of the bench marks during the time interval between different leveling epochs. Adjusted NAVD 88 are computed for posted bench marks by supplemental adjustments. A range of mean distribution rate corrections is listed for each posted bench mark in the data portion of the publication. A summary table of the mean distribution rates and their codes is listed below. The mean distribution rate corrections which were applied to the original leveling observations is a good indication of the usefulness of the posted bench marks' adjusted NAVD 88 heights. POSTED BENCH MARKS SHOULD BE USED WITH CAUTION. As is the case for all leveling projects, the mandatory FGCS check leveling two-mark or three-mark tie procedure will usually detect any isolated movement (or other problem) at an individual bench mark. Of course, regional movement affecting all the marks equally is not detected by the two- or three-mark tie procedure.
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ELLP_ORDER |
Order of accuracy for the ELLIP_HT Should be 1,2,3,4, or 5 if present. The following ellipsoid height order and class relative accuracy standards have not yet been adopted by the Federal Geodetic Control Subcommittee, but are currently in use by NGS-. The ellipsoid height difference accuracy (b) is computed from a a minimally constrained correctly weighted least squares adjustment by - b = s / sqrt(d) where b = height difference accuracy s = propagated standard deviation of ellipsoid height difference in millimeters between control points obtained from the least squares adjustment. d = horizontal distance between control points in kilometers
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ELLP_CLASS |
Class of accuracy for ELLIP_HT Should be 1 or 2 See details under ELLP_ORDER |
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FIRST_RECV |
Date when the station was first monumented or in the case of landmarks, first observed. |
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LAST_RECV |
Date when the station was last recovered. |
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LAST_COND |
Last recovered condition of the mark. Should be one of the following- MONUMENTED FIRST OBSERVED GOOD POOR MARK NOT FOUND SEE DESCRIPTION DESTROYED |
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LAST_RECBY |
Agency who reported the last condition of the mark. |
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SAT_USE |
Undefined by Source |
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SAT_DATE |
Undefined by Source |
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STABILITY |
The stability of the mark may have 1 of 4 codes as indicated below-
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DESCRIPT |
GeoPlan added field based on QUAD |
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FGDLAQDATE |
Date GeoPlan acquired data from source |
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AUTOID |
Unique ID added by GeoPlan |
FGCS sponsored testing in cooperation with equipment manufacturers and National Institutes of Standards and Technology, Gaithersburg, MD 20850 |
This dataset DOES NOT include destroyed marks. All other non-publishable marks are NOT included. Non-publishable criteria is available at <http://www.ngs.noaa.gov/cgi-bin/craigs_lib.prl?HELP_NONPUB=1> |
Horizontal control stations (those with precise Latitude, Longitude) were established in accordance with FGDC publications "Standards and Specifications for Geodetic Accuracy Standards" and "Geometric Geodetic Accuracy Standards and Specifications for Using GPS Relative Positioning Techniques" The final Latitude, Longitude of these stations were determined by a least squares adjustments of the horizontal observations. Horizontal control station have Latitude, Longitudes displayed to 5 places and are identified by attribute POS_SRCE = 'ADJUSTED' Lesser quality Latitude, Longitudes may also be preset in the dataset. These are identified by a POS_SRCE attributes HD_HELD1, HD_HELD2, or SCALED. These lesser quality positions are described at: <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=SCALED> Vertical control stations (those with precise Orthometric Heights) were established in accordance with FGDC publications "Standards and Specifications for Geodetic Accuracy Standards" The final Orthometric Height of these stations were in most cases determined by a least squares adjustments of the vertical observations but in some cases may have been keyed from old survey documents. Vertical control stations have Orthometric Heights displayed to 2 or 3 places and are identified by attribute ELEV_SRCE of ADJUSTED, ADJ UNCH, POSTED,READJUST,N HEIGHT,RESET,COMPUTED Lesser quality Orthometric Heights may also be preset in the dataset. These are identified by a ELEV_SRCE attributes GPS_OBS, VERT_ANG, H_LEVEL, VERTCON, SCALED. These lesser quality orthometric heights are described at: <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=SCALED> IMPORTANT - Control stations do not always have both precise Latitude, Longitude AND precise Orthometric Height. A horizontal control station may have a orthometric height associated with it which is of non geodetic quality. These types of heights are displayed to 0, 1, or 2 decimal places. Worst case being off by +/- 1 meter. LIKEWISE - A Vertical control station may have a Latitude, Longitude associated with it which is of non geodetic quality. These types of Latitude, Longitudes are displayed to 0, 1 or 2 decimal places. Worst case being off by +/- 180 meter. Refer to <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=SCALED> for a description of the various type of methods used in determining the Latitude, Longitude, and Orthometric Height. Attribute POS_CHECK and ELEV_CHECK indicate whether or not an observational check was made to the position and/or orthometric height. Care should be taken when using "No Check" coordinates. If attribute ELEV_SRCE = 'VERTCON' then the Orthometric Height was determined by applying NGS program VERTCON to an Old NGVD 29 height. In most areas VERTCON gives results to +/- 2 cm. See <http://www.ngs.noaa.gov/TOOLS/Vertcon/vertcon.html> for a more detailed explanation of VERTCON accuracy. Ellipsoid Heights are also present in the dataset. The ellipsoid heights consist of those determined using a precise geoid model, which are displayed to 2 decimal places and are considered good to +/- .005 meters, and those displayed to 1 decimal place and are considered only good to +/- .5 meters |
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Provide a base of reference for latitude, longitude and height throughout the United States. |
The description of tests are explained in "Geometric Geodetic Accuracy Standards and Specifications For Using GPS Relative Positioning Techniques," FGCS (formally FGCC) publication version 5.0, 1989. |
The description of tests are explained in "Geometric Geodetic Accuracy Standards and Specifications for Using GPS Relative Positioning Techniques," FGCS (formally FGCC) publication version 5.0, 1989, (See table 1, p6). |
Not restricted; Geodetic Data, including software were developed and compiled with U.S. Government funding; no proprietary rights may be attached to them nor may they be sold to the U.S. Government as part of any procurement of ADP products or services. |
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 |
National Geodetic Survey: http://www.ngs.noaa.gov/ |
The National Geodetic Survey produces geodetic data. Geodetic data comprise the results of geodetic surveys to determine, among other things, latitude, longitude, height, scale, and orientation control. The National Geodetic Survey original field survey project observations and final reports are accessioned into records system of the National Archives and Records Administration of the U.S.A. These surveys provide information valuable for a variety of uses in the mapping, charting and surveying community. The NGS' final product is the geodetic data sheet. Geodetic data sheets are comprehensive summaries of all published information for a given geodetic reference point, including: the geographic position and/or height based on the current reference datum, condition of the survey mark when it was last visited, a description of where the point is located and how to reach it, and an explanation of the terms used in the data sheet. In support of these geodetic data, the NGS provides software, publications, and various user services, including geodetic advisor program, instrument calibration, surveying standards, and technical workshops. This dataset contains certain information extracted from the above mentioned data sheet. Process Date: Not complete |
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: |
National Oceanic & Atmospheric Administration, National Geodetic Survey NOAA, NGS SSMC2/9152 1315 East-west Highway Silver Spring, MD 20910 301-713-3242 |
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