Horizontal and Vertical Geodetic Control Data for the Unites States.

Metadata also available as

Metadata:

Identification_Information:
Citation:
Citation_Information:
Originator: NOAA, National Geodetic Survey
Publication_Date: 20220102
Title:
Horizontal and Vertical Geodetic Control Data for the Unites States.
Edition: latest available
Geospatial_Data_Presentation_Form: Diagram
Series_Information:
Series_Name: N/A
Issue_Identification: N/A
Publication_Information:
Publication_Place: NOAA Campus, Silver Spring, MD
Publisher: NOAA, National Geodetic Survey
Other_Citation_Details:
Questions concerning this data may be addressed to NGS Information Services Branch EMail - ngs.software@noaa.gov Phone - 301-713-3242
Description:
Abstract:
This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Downloaded by the Hawaii Statewide GIS Program from NGS, 1/28/22. Each geodetic control station in this dataset has either a precise Latitude/Longitude used for horizontal control or a precise Orthometric Height used for vertical control, or both. The National Geodetic Survey (NGS) serves as the Nation's depository for geodetic data. The NGS distributes geodetic data worldwide to a variety of users. These geodetic data include the final results of geodetic surveys, software programs to format, compute, verify, and adjust original survey observations or to convert values from one geodetic datum to another, and publications that describe how to obtain and use Geodetic Data products and services. Note: This data was projected to the State's standard projection/datum of UTM Zone 4, NAD 83 HARN for use in the State's GIS database, The State posts an un-projected version of the layer on its legacy site (https://planning.hawaii.gov/gis/download-gis-data-expanded/#013), or users can visit the National Geodetic Survey site directly, at https://www.ngs.noaa.gov/cgi-bin/sf_archive.prl. For additional information, please see metadata at https://files.hawaii.gov/dbedt/op/gis/data/ngs_geodetic_ctrl_stns_summary.pdfor contact Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii; PO Box 2359, Honolulu, Hi. 96804; (808) 587-2846; email: gis@hawaii.gov; Website: https://planning.hawaii.gov/gis.
Purpose:
Provide a base of reference for latitude, longitude and height throughout the United States. This data contains a set of geodetic control stations maintained by the National Geodetic Survey. Downloaded by the Hawaii Statewide GIS Program from NGS, 1/28/22. Each geodetic control station in this dataset has either a precise Latitude/Longitude used for horizontal control or a precise Orthometric Height used for vertical control, or both. The National Geodetic Survey (NGS) serves as the Nation's depository for geodetic data. The NGS distributes geodetic data worldwide to a variety of users. These geodetic data include the final results of geodetic surveys, software programs to format, compute, verify, and adjust original survey observations or to convert values from one geodetic datum to another, and publications that describe how to obtain and use Geodetic Data products and services. Note: This data was projected to the State's standard projection/datum of UTM Zone 4, NAD 83 HARN for use in the State's GIS database, The State posts an un-projected version of the layer on its legacy site (https://planning.hawaii.gov/gis/download-gis-data-expanded/#013), or users can visit the National Geodetic Survey site directly, at https://www.ngs.noaa.gov/cgi-bin/sf_archive.prl. For additional information, please see metadata at https://files.hawaii.gov/dbedt/op/gis/data/ngs_geodetic_ctrl_stns_summary.pdf or contact Hawaii Statewide GIS Program, Office of Planning and Sustainable Development, State of Hawaii; PO Box 2359, Honolulu, Hi. 96804; (808) 587-2846; email: gis@hawaii.gov; Website: https://planning.hawaii.gov/gis.
Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 20220102
Currentness_Reference: retrieval date
Status:
Progress: Complete
Maintenance_and_Update_Frequency: Continually
Spatial_Domain:
Bounding_Coordinates:
West_Bounding_Coordinate: -178.293929
East_Bounding_Coordinate: -154.454330
North_Bounding_Coordinate: 29.808472
South_Bounding_Coordinate: 18.089050
Keywords:
Theme:
Theme_Keyword_Thesaurus: geodesy
Theme_Keyword: NSRS
Theme_Keyword: geodetic
Theme_Keyword: horizontal control
Theme_Keyword: vertical control
Theme_Keyword: ellipsoid height
Theme_Keyword: benchmark
Theme_Keyword: orthometric height
Theme_Keyword: latitude
Theme_Keyword: longitude
Place:
Place_Keyword_Thesaurus: None
Place_Keyword: The geographic limits of USA including trust Territories
Stratum:
Stratum_Keyword_Thesaurus: N/A
Stratum_Keyword: N/A
Temporal:
Temporal_Keyword_Thesaurus: N/A
Temporal_Keyword: N/A
Access_Constraints:
Geodetic Data are in the public domain, not restricted from access or distribution.
Use_Constraints:
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.
Point_of_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA, National Geodetic Survey
Contact_Person: NGS Information Services Branch
Contact_Position: Information Specialist
Contact_Address:
Address_Type: mailing and physical
Address: SSMC3/9202 1315 East-west Highway
City: Silver Spring
State_or_Province: MD
Postal_Code: 20910
Country: US
Contact_Voice_Telephone: 301-713-3242
Contact_Facsimile_Telephone: 301-713-4172
Contact_Electronic_Mail_Address: ngs.infocenter@noaa.gov
Hours_of_Service: 7:00am to 4:30pm EST
Contact_Instructions: Prefer EMail
Data_Set_Credit: NOAA, National Geodetic Survey and cooperating organizations
Security_Information:
Security_Classification_System: DOD
Security_Classification: Unclassified
Security_Handling_Description: none
Native_Data_Set_Environment: Version 6.2 (Build 9200) ; Esri ArcGIS 10.8.1.14362
Data_Quality_Information:
Attribute_Accuracy:
Attribute_Accuracy_Report:
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
Quantitative_Attribute_Accuracy_Assessment:
Attribute_Accuracy_Value: 95 percent confidence level for geodetic quality data.
Attribute_Accuracy_Explanation:
Geodetic Data are continuously being processed; their standards and specifications are being reviewed for next publication release. "Standards and Specifications for Geodetic Control Networks", 1984 and "Geometric Geodetic Accuracy Standards and Specifications for Using GPS Relative Positioning Techniques," FGCS (formally FGCC) publication version 5.0 1989, are most current published documents.
Logical_Consistency_Report:
FGCS sponsored testing in cooperation with equipment manufacturers and National Institutes of Standards and Technology, Gaithersburg, MD 20850
Completeness_Report:
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>
Positional_Accuracy:
Horizontal_Positional_Accuracy:
Horizontal_Positional_Accuracy_Report:
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.
Quantitative_Horizontal_Positional_Accuracy_Assessment:
Horizontal_Positional_Accuracy_Value: .05 meters for highest order of accuracy
Horizontal_Positional_Accuracy_Explanation:
Horizontal positional accuracy statements pertain to horizontal control stations only. i.e. Those with geodetic quality Latitude, Longitudes. Positional Accuracy explanation contained 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). with the exception of Order A and Order B which have an accuracy of as described at: <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=HORZ%20ORDER>
Vertical_Positional_Accuracy:
Vertical_Positional_Accuracy_Report:
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).
Quantitative_Vertical_Positional_Accuracy_Assessment:
Vertical_Positional_Accuracy_Value: .05 meter for highest order of accuracy
Vertical_Positional_Accuracy_Explanation:
Vertical positional accuracy statements pertain to vertical control stations only. i.e. Those with geodetic quality Orthometric Heights. Orthometric Height accuracy explanation is contained in FGDC publication "Standards and Specifications for Geodetic Control Networks" with the exception of vertical control of class 0 POSTED and READJUSTED Heights which are described at: <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=VERT%20ORDER> Ellipsoid height accuracy explanation contained 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). The accuracies for ellipsoid heights are described at: <http://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=ELLP%20ORDER>
Lineage:
Source_Information:
Source_Citation:
Citation_Information:
Originator: NOAA, National Geodetic Survey
Publication_Date: 20220102
Title:
"Input Formats and Specifications of the National Geodetic Survey Data Base" published by FGCS (formally FGCC)
Edition: latest available
Geospatial_Data_Presentation_Form: diagram
Series_Information:
Series_Name: N/A
Issue_Identification: N/A
Publication_Information:
Publication_Place: NOAA Campus, Silver Spring, MD
Publisher: NOAA, National Geodetic Survey
Other_Citation_Details: N/A
Type_of_Source_Media: hardcopyPaper
Source_Time_Period_of_Content:
Time_Period_Information:
Single_Date/Time:
Calendar_Date: 19940101
Source_Currentness_Reference: publication date
Source_Citation_Abbreviation: Blue Book
Source_Contribution:
The geodetic data must be submitted in the digital formats specified in the FGCS (formally FGCC) publication "Input Formats and Specifications of the National Geodetic Survey Data Base" which describes the formats and procedures for submission of data for adjustment and assimilation into the National Geodetic Survey Data Base. Separate volumes of this publication refer to horizontal (volume 1), vertical (volume 2), and gravity (volume 3) control, and are available from NOAA, National Geodetic Survey, 1315 East-West Hwy, Code N/CGS1, Silver Spring, MD, 20910 (1-301-713-3242). Note guidelines for submission of three-dimensional Global Positioning System (GPS) relative positioning data are contained in annex L to volume 1.
Process_Step:
Process_Description:
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.
Source_Used_Citation_Abbreviation: Geodetic Data
Process_Date: not complete
Source_Produced_Citation_Abbreviation: NOAA, National Geodetic Survey and cooperating organizations.
Process_Contact:
Contact_Information:
Contact_Person_Primary:
Contact_Person: NGS Information Services Branch
Contact_Position: Information Specialist
Contact_Address:
Address_Type: mailing and physical
Address: SSMC3/9202 1315 East-west Highway
City: Silver Spring
State_or_Province: MD
Postal_Code: 20910
Country: US
Contact_Voice_Telephone: 301-713-3242
Contact_Facsimile_Telephone: 301-713-4172
Contact_Electronic_Mail_Address: ngs.infocenter@noaa.gov
Hours_of_Service: 9:00am to 4:30pm EST
Contact_Instructions: Prefer EMail
Spatial_Data_Organization_Information:
Indirect_Spatial_Reference:
Geodetic Data- horizontal positional datum conversion, use program NADCON (version 2.1) Geodetic Data - vertical positional datum conversion, use program VERTCON (version 2.0) These programs provide indirect spatial reference data and are available from NOAA, National Geodetic Survey at <http://www.ngs.noaa.gov/PC_PROD/pc_prod.shtml>
Direct_Spatial_Reference_Method: Vector
Point_and_Vector_Object_Information:
SDTS_Terms_Description:
SDTS_Point_and_Vector_Object_Type: Entity point
Point_and_Vector_Object_Count: 3678
Spatial_Reference_Information:
Horizontal_Coordinate_System_Definition:
Planar:
Map_Projection:
Map_Projection_Name: NAD 1983 HARN UTM Zone 4N
Transverse_Mercator:
Scale_Factor_at_Central_Meridian: 0.9996
Longitude_of_Central_Meridian: -159.0
Latitude_of_Projection_Origin: 0.0
False_Easting: 500000.0
False_Northing: 0.0
Planar_Coordinate_Information:
Planar_Coordinate_Encoding_Method: coordinate pair
Coordinate_Representation:
Abscissa_Resolution: 0.0001
Ordinate_Resolution: 0.0001
Planar_Distance_Units: meter
Geodetic_Model:
Horizontal_Datum_Name: D North American 1983 HARN
Ellipsoid_Name: GRS 1980
Semi-major_Axis: 6378137.0
Denominator_of_Flattening_Ratio: 298.257222101
Entity_and_Attribute_Information:
Detailed_Description:
Entity_Type:
Entity_Type_Label: ngs_geodetic_ctrl_stns
Attribute:
Attribute_Label: OBJECTID
Attribute_Definition: Internal feature number.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:
Unrepresentable_Domain:
Sequential unique whole numbers that are automatically generated.
Attribute:
Attribute_Label: Shape
Attribute_Definition: Feature geometry.
Attribute_Definition_Source: Esri
Attribute_Domain_Values:
Unrepresentable_Domain: Coordinates defining the features.
Attribute:
Attribute_Label: FeatureId
Attribute:
Attribute_Label: DATA_DATE
Attribute:
Attribute_Label: DATA_SRCE
Attribute:
Attribute_Label: DEC_LONG
Attribute:
Attribute_Label: DEC_LAT
Attribute:
Attribute_Label: PID
Attribute:
Attribute_Label: NAME
Attribute:
Attribute_Label: STATE
Attribute:
Attribute_Label: COUNTY
Attribute:
Attribute_Label: QUAD
Attribute:
Attribute_Label: LATITUDE
Attribute:
Attribute_Label: LONGITUDE
Attribute:
Attribute_Label: POS_DATUM
Attribute:
Attribute_Label: DATUM_TAG
Attribute:
Attribute_Label: POS_SRCE
Attribute:
Attribute_Label: ELEVATION
Attribute:
Attribute_Label: ELEV_DATUM
Attribute:
Attribute_Label: ELEV_SRCE
Attribute:
Attribute_Label: ELLIP_HT
Attribute:
Attribute_Label: ELLIP_SRCE
Attribute:
Attribute_Label: POS_ORDER
Attribute:
Attribute_Label: POS_CHECK
Attribute:
Attribute_Label: ELEV_ORDER
Attribute:
Attribute_Label: ELEV_CLASS
Attribute:
Attribute_Label: ELEV_CHECK
Attribute:
Attribute_Label: DIST_RATE
Attribute:
Attribute_Label: ELLP_ORDER
Attribute:
Attribute_Label: ELLP_CLASS
Attribute:
Attribute_Label: FIRST_RECV
Attribute:
Attribute_Label: LAST_RECV
Attribute:
Attribute_Label: LAST_COND
Attribute:
Attribute_Label: LAST_RECBY
Attribute:
Attribute_Label: SAT_USE
Attribute:
Attribute_Label: SAT_DATE
Attribute:
Attribute_Label: STABILITY
Overview_Description:
Entity_and_Attribute_Overview:
The current attributes and their meaning are shown below.
#FeatureId Temporary unique ID assigned to this station.
DATA_DATE- The date when this information was retrieved from the NGS database.
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.
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.
DEC_LAT- Decimal equivalent of the LATITUDE
PID- Permanent Identifier assigned by NGS to each mark
NAME- Station Name (a.k.a. Designation)
STATE- State Code
COUNTY- County Name
QUAD- USGS Topographic Quad Map Name
LATITUDE- Latitude in Deg-Min-Sec format
LONGITUDE- Longitude in Deg-Min-Sec format
POS_DATUM- Datum of the LATITUDE,LONGITUDE Should always be NAD83
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.
POS_SRCE- Position Source for the LATITUDE,LONGITUDE
ADJUSTED = Least squares adjustment. (Lat,Lon Rounded to 5 decimal places.)
HD_HELD1 = Differentially corrected hand held GPS observations. (Lat,Lon Rounded to 2 decimal places.)
HD_HELD2 = Autonomous hand held GPS observations. (Lat,Lon Rounded to 1 decimal places.)
SCALED = Scaled from a topographic map. (Lat,Lon Rounded to 0 decimal places.)
ORTHO_HT- Present if available. The Orthometric Height in METERS indicating the height above the Geoid.
VERT_DATUM- Datum of the ORTHO_HT
VERT_SRCE- Vertical Source for the ORTHO_HT
ADJUSTED = Direct Digital Output from Least Squares Adjustment of Precise Leveling. (Rounded to 3 decimal places.)
ADJ UNCH = Manually Entered (and NOT verified) Output of Least Squares Adjustment of Precise Leveling. (Rounded to 3 decimal places.)
POSTED = Pre-1991 Precise Leveling Adjusted to the NAVD 88 Network After Completion of the NAVD 88 General Adjustment of 1991. (Rounded to 3 decimal places.)
READJUST = Precise Leveling Readjusted as Required by Crustal Motion or Other Cause. (Rounded to 2 decimal places.)
N HEIGHT = Computed from Precise Leveling Connected at Only One Published Bench Mark. (Rounded to 2 decimal places.)
RESET = Reset Computation of Precise Leveling. (Rounded to 2 decimal places.)
COMPUTED = Computed from Precise Leveling Using Non-rigorous Adjustment Technique. (Rounded to 2 decimal places.)
LEVELING = Precise Leveling Performed by Horizontal Field Party. (Rounded to 2 decimal places.)
H LEVEL = Level between control points not connected to bench mark. (Rounded to 1 decimal places.)
GPS OBS = Computed from GPS Observations. (Rounded to 1 decimal places.)
VERT ANG = Computed from Vertical Angle Observations. (Rounded to 1 decimal place; If No Check, to 0 decimal places.)
SCALED = Scaled from a Topographic Map. (Rounded to 0 decimal places.)
U HEIGHT = Unvalidated height from precise leveling connected at only one NSRS point. (Rounded to 2 decimal places.)
VERTCON = The NAVD 88 height was computed by applying the VERTCON shift value to the NGVD 29 height. (Rounded to 0 decimal places.)
ELLIP_HT- Present if available. The ellipsoid height in METERS referenced to GRS80 ellipsoid.
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.
VERT_ORDER- Order of accuracy for the ORTHO_HT 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.
Vertical 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-
Vertical Order/Class Tolerance Factor -------------------- ---------------- 1 class 0 2.0 mm or less 2 class 0 8.4 mm or less 3 class 0 12.0 mm or less
VERT_CLASS- Should be 0, 1, or 2 See details under ELEV_ORDER
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.
Distribution Distribution Rate Code Rate Correction ------------ --------------- "a" 0.0 thru 1.0 mm/km "b" 1.1 thru 2.0 " "c" 2.1 thru 3.0 " "d" 3.1 thru 4.0 " "e" 4.1 thru 8.0 " "f" greater than 8.0 mm/km
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.
FIRST_RECV- Date when the station was first monumented or in the case of landmarks, first observed.
LAST_RECV- Date when the station was last recovered.
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
LAST_RECBY- Agency who reported the last condition of the mark.
STABILITY- The stability of the mark may have 1 of 4 codes as indicated below- A = MOST RELIABLE AND EXPECTED TO HOLD POSITION/ELEVATION WELL B = PROBABLY HOLD POSITION/ELEVATION WELL C = MAY HOLD, BUT OF TYPE COMMONLY SUBJECT TO SURFACE MOTION - E.G. FROST HEAVE, ETC D = MARK OF QUESTIONABLE OR UNKNOWN STABILITY
HT_MOD- Designates if this site is a Height Modernization site. Y - Yes.
CORS_ID- Continuously Operating Reference Stations (CORS) site ID.
PACS_SACS- Designates whether this is a Primary Airport Control Station (PACS) or Secondary Airport Control Station (SACS).
GEOID_HT- Present if available. The geoid height in METERS referenced to the geoid model attribute.
N_ACC_HZ- Horizontal network accuracy at the 95 percent confidence level (cm).
N_ACC_EL- Ellipsoid height network accuracy at the 95 percent confidence level (cm).
N_ACC_STD_N- North component of coordinate standard deviation (latitude), used to compute horizontal network accuracy (cm).
N_ACC_STD_E- East component of coordinate standard deviation (longitude), used to compute horizontal network accuracy (cm).
N_ACC_STD_H- Up component of coordinate standard deviation (ellipsoid height), used to compute ellipsoid height network accuracy (cm).
N_ACC_CORR- Correlation coefficient between north and east components of coordinate standard deviation (latitude and longitude), used to compute horizontal network accuracy (unitless).
ECEF_X- The computed Earth-Centered, Earth-Fixed X position.
ECEF_Y- The computed Earth-Centered, Earth-Fixed Y position.
ECEF_Z- The computed Earth-Centered, Earth-Fixed Z position.
SPC_ZONE- The State Plane Coordinate Zone.
SPC_NORTH- The State Plane Coordinate Northing.
SPC_EAST- The State Plane Coordinate Easting.
SPC_CONV- The State Plane Coordinate Convergence Angle.
SPC_CSF- The State Plane Coordinate Combined Scale Factor.
UTM_ZONE- The Universal Transverse Mercator Zone.
UTM_NORTH- The Universal Transverse Mercator Northing.
UTM_EAST- The Universal Transverse Mercator Easting.
UTM_CONV- The Universal Transverse Mercator Convergence Angle.
UTM_CSF- The Universal Transverse Mercator Combined Scale Factor.
DYNAMIC_HT- The computed dynamic height at a bench mark using the orthometric height referenced the NAVD 88 and a gravity value.
MODELEDGRAV- The interpolated gravity value which was used in the NAVD 88 general adjustment.
MARKER- Identifies the type of marker.
SETTING- Identifies the type of setting.
STAMPING- Identifies the stamping on the disk.
Entity_and_Attribute_Detail_Citation:
All values were obtained from the NGA Datasheet available at <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl>
Distribution_Information:
Distributor:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA, National Geodetic Survey
Contact_Person: NGS Information Services Branch
Contact_Position: Information Specialist
Contact_Address:
Address_Type: mailing and physical
Address: SSMC3/9202 1315 East-west Highway
City: Silver Spring
State_or_Province: MD
Postal_Code: 20910
Country: US
Contact_Voice_Telephone: 301-713-3242
Contact_Facsimile_Telephone: 301-713-4172
Contact_Electronic_Mail_Address: ngs.infocenter@noaa.gov
Hours_of_Service: 9:00am to 4:30pm EST
Contact_Instructions: Prefer EMail
Resource_Description:
Distributed through <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl>
Distribution_Liability: The distributor does not assume liability
Standard_Order_Process:
Digital_Form:
Digital_Transfer_Information:
Format_Name: ShapeFile
Format_Version_Number: 1.0; 2013
File_Decompression_Technique: Download options include PC Zip and Unix compressed tar
Digital_Transfer_Option:
Fees: free if you retrieve it yourself
Metadata_Reference_Information:
Metadata_Date: 20220219
Metadata_Contact:
Contact_Information:
Contact_Organization_Primary:
Contact_Organization: NOAA, National Geodetic Survey
Contact_Person: NGS Information Services Branch
Contact_Position: Information Specialist
Contact_Address:
Address_Type: mailing and physical
Address: SSMC3/9202 1315 East-west Highway
City: Silver Spring
State_or_Province: MD
Postal_Code: 20910
Country: US
Contact_Voice_Telephone: 301-713-3242
Contact_Facsimile_Telephone: 301-713-4172
Contact_Electronic_Mail_Address: ngs.software@noaa.gov
Hours_of_Service: 9:00am to 4:30pm EST
Contact_Instructions: Prefer EMail
Metadata_Standard_Name: FGDC Content Standard for Digital Geospatial Metadata
Metadata_Standard_Version: FGDC-STD-001-1998
Metadata_Time_Convention: local time
Metadata_Access_Constraints:
Geodetic Data are in the public domain, not restricted from access or distribution.
Metadata_Use_Constraints:
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.
Metadata_Security_Information:
Metadata_Security_Classification_System: DOD
Metadata_Security_Classification: Unclassified
Metadata_Security_Handling_Description: none
Generated by mp version 2.9.12 on Sat Feb 26 15:00:49 2022