NOAA, National Geodetic Survey 20190402 latest available Diagram N/A N/A NOAA Campus, Silver Spring, MD NOAA, National Geodetic Survey Questions concerning this data may be addressed to NGS Information Services Branch EMail - ngs.software@noaa.gov Phone - 301-713-3242 <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl> This data contains a set of geodetic control stations maintained by the National Geodetic Survey. 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. Provide a base of reference for latitude, longitude and height throughout the United States. 20190402 retrieval date Complete Continually -73.5 -69.9 42.9 41.2 geodesy NSRS, geodetic, horizontal control, vertical control, ellipsoid height, benchmark, orthometric height, latitude, longitude None The geographic limits of USA including trust Territories N/A N/A N/A N/A Geodetic Data are in the public domain, not restricted from access or distribution. 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. NGS Information Services Branch NOAA, National Geodetic Survey Information Specialist Mailing and Physical Address

SSMC3/9202 1315 East-west Highway

Silver Spring MD 20910 USA 301-713-3242 301-713-4172 ngs.infocenter@noaa.gov 7:00am to 4:30pm EST Prefer EMail NOAA, National Geodetic Survey and cooperating organizations DOD unclassified none The data was extracted from NGS datasheets which are available at <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl> The NGS datasheet is a text document which summarizes key geodetic information stored in the NGS database. 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 95 percent confidence level for geodetic quality data. 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. 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> 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. .05 meters for highest order of accuracy 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> 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). .05 meter for highest order of accuracy 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> NOAA, National Geodetic Survey 20190402 latest available diagram N/A N/A NOAA Campus, Silver Spring, MD NOAA, National Geodetic Survey N/A <http://www.ngs.noaa.gov/FGCS/BlueBook/> paper, Web 1994 publication date Blue Book 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. 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. Geodetic Data Not complete NOAA, National Geodetic Survey and cooperating organizations. NGS Information Services Branch Information Specialist Mailing and Physical Address

SSMC3/9202 1315 East-west Highway

Silver Spring MD 20910 USA 301-713-3242 301-713-4172 ngs.infocenter@noaa.gov 9:00am to 4:30pm EST Prefer EMail 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> point point 1,500,000 0.00001 0.00001 degrees, minutes, and decimal seconds North American Datum of 1983 (NAD 83) Geodetic Reference System 80 (GRS80) 6378137 298.26 North American Vertical Datum of 1988 (NAVD 88), including Ellipsoidal and Orthometric Heights. .01 meters implicit coordinate the local surface .01 meters implicit coordinate 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. All values were obtained from the NGA Datasheet available at <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl> NGS Information Services Branch NOAA, National Geodetic Survey Information Specialist Mailing and Physical Address

SSMC3/9202 1315 East-west Highway

Silver Spring MD 20910 USA 301-713-3242 301-713-4172 ngs.infocenter@noaa.gov 9:00am to 4:30pm EST Prefer EMail Datasheet Shapefile The distributor does not assume liability ShapeFile 1.0 2013 Download options include PC Zip and Unix compressed tar <http://www.ngs.noaa.gov/cgi-bin/datasheet.prl?Explain=ShapeFiles> Distributed through http://www.ngs.noaa.gov/cgi-bin/datasheet.prl SUN Solaris free if you retrieve it yourself 20130513 NGS Information Services Branch NOAA, National Geodetic Survey Information Specialist Mailing and Physical Address

SSMC3/9202 1315 East-west Highway

Silver Spring MD 20910 USA 301-713-3242 301-713-4172 ngs.software@noaa.gov 9:00am to 4:30pm EST Prefer EMail FGDC Content Standards for Digital Geospatial Metadata FGDC-STD-001-1998 local time Geodetic Data are in the public domain, not restricted from access or distribution. 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. DOD unclassified none N/A N/A