This data set depicts the estimated horizontal locations of some 1,700 + City of Long Beach Survey Benchmarks. A survey benchmark is a permanent marker established by a land surveyor to provide elevation reference to a defined vertical datum. More precise locations are provided in the descriptions of the individual benchmarks contained within the Survey Benchmark Book published on the City website (longbeach.gov/pw/resources/maps/). The elevations shown therein are based upon measurements made through conventional differential leveling methods. The latest comprehensive inventory, measurement and adjustment of citywide benchmarks was made in 1985. The network is referenced to the National Geodetic Vertical Datum of 1929 (NGVD29) and is based upon an elevation of +11.129 feet on the tidal benchmark named “Tidal 8” located at Berth 69 of Municipal Pier No.1 in the Los Angeles Outer Harbor. The intention of the benchmark list is to provide vertical elevation data to the public on city-maintained benchmarks. As with all survey data, care should be taken to verify the benchmark elevations by measuring multiple benchmarks. The horizontal locations contained in the data set are only approximate and intended exclusively for geographical representation for project planning purposes. Please report any inconsistencies in this data to the Surveying department at the City of Long Beach by phone at (562)570-3093 or by email at CLBSurvey@longbeach.gov.For more information, see Surveying Practice - California Business & Professions Code, Chapter 15; Article 5; Section 8771.”

These are locations that are to be used as an elevation reference and contain the official elevation and last known latitude and longitude.

This layer contains the data for the survey control points and benchmarks for the City of Round Rock, located in Williamson County, Texas. This layer is part of an original dataset provided and maintained by the City of Round Rock GIS/IT Department. The data in this layer are represented as points. A survey benchmark is a reference point that is used to calculate something. A benchmark, in surveying, can be referred to a permanent mark created at a recognized height which is used as the basis for measuring different altitudes of topographical points.A survey control point is an accurately surveyed coordinate location for a physical feature that can be identified on the ground. This layer contains information about each point's type, project title, firm, location, date, and vertical datum used if applicable. Prior to the digitization of these survey benchmarks and control points, a previous survey was completed in 2004 which established 41 control points throughout the city. Those points have been added to this layer, but you can still view their documentation in the following paragraph:Find the control point nearest your area to determine the corresponding data sheet, and find the download link below. You can also download the monument coordinates and report synopsis.GPS Point Data Sheets:01-001 01-002 01-003 01-00401-005 01-006 01-007 01-00801-009 01-010 01-011 01-01201-013 01-014 01-015 01-01601-017 01-018 01-019 01-02001-021 01-022 01-023 01-02401-025 01-026 01-027 01-02801-029 01-030 01-031 01-03201-033 01-034 01-035 01-03601-037 01-038 01-039 01-04001-041

This is a point data set representing monumented vertical geodetic survey control points (a.k.a. elevation benchmarks) established by the City of Boise. A benchmark is a physical marker, monument, or demarcation established by a surveyor for horizontal and/or vertical measurement control. This data set only contains benchmarks established by the City of Boise that are based on the North American Vertical Datum of 1988 (NAVD 88); benchmarks established under other vertical datums are not included. The elevation values in this data set are based on the vertical control from the National Geodetic Survey (NGS), the U. S. Geological Survey (USGS), and some state owned vertical control. The horizontal location is obtained by Global Positioning System (GPS) data collection of the surveyed benchmark. Attribute data including elevation, is transcribed from surveying field books supplied by Boise City Public Works survey personnel. Data Attributes:MARK TYPE: ALCAP - Aluminum Cap, BRASSCAP - Brass Cap, CHISELSQ - physically carved square, PK - A steel masonry nail manufactured by Parker Kaelon (PK nail), OTHER - Any other survey marker type.LOCATION: Nearest street or cross streets to the benchmark.ELEVATION: The vertical elevation in feet above sea level as established from survey calculations based on the 1988 NAVD Datum.GPS DATE: Date the benchmark was captured by GPS.COMMENTS: Pertinent notes on general description and location of the benchmark.BOOK: The City of Boise Public Works surveying field book number the benchmark was established under.PAGE: The City of Boise Public Works surveying field book page the benchmark was established under.The data set is maintained by the Boise City Public Works GIS staff. The data is updated continuously. It is current to the date it was published.For more information, please visit Ada County Control Information or City of Boise Public Works.

The Datum of the majority of the City of Sacramento benchmarks is the National Geodetic Vertical Datum of 1929 (NGVD 29) and was based upon a plane datum with reference to four U.S. Government monuments. Some North American Vertical Datum 1988 (NAVD 88) differential baselines have been conducted and the elevations of those benchmarks have been included and identified in this database.VERTICAL CONTROL DISCLAIMER AND GENERAL USE DISCLAIMER City of Sacramento Vertical Control Network, also known as “City of Sacramento Datum” information, is furnished by the Department of Public Works - Engineering Services. It was developed and collected for the purpose of establishing reference points for all survey activities within Sacramento City limits. City of Sacramento makes no warranties, expressed or implied, concerning the accuracy, completeness, reliability, or suitability of this data for any other particular use. Furthermore, the City of Sacramento assumes not liability for any errors, omissions, or inaccuracies associated with the use or misuse of such data. The City of Sacramento tries to keep this information current and accurate.If you find a missing or destroyed City of Sacramento benchmark please contact the City Land Surveyor by calling (916) 808-8777.

ACCEPTABLE USE The City of Sacramento Datum (unadjusted NGVD29) local benchmarks provided here are acceptable as City of Sacramento benchmarks for the purpose of establishing and extending vertical control to design surveys. Reference Sacramento City Code, §1.12.010.All information compiled on this website is provided as a public service and for general informational purposes only. In preparation of these pages, every effort has been made by the Department of Public Works - Engineering Services to offer the most current, correct and concise information possible. The City of Sacramento and its authorized agents and contractors disclaim any responsibility for typographical errors and accuracy of the information that may be contained on the City of Sacramento website; www.cityofsacramento.orgBy accessing the information, data, materials and links contained in the City of Sacramento World Wide Web pages, you hereby agree to and accept the following terms and conditions: The Department of Public Works - Engineering Services shall not be liable for the improper or incorrect use of data, information, materials, links or related graphics described and /or contained herein. The Department of Public Works - Engineering Services shall not be liable for any demand claim, regardless of form or action, arising out of or incident to the posting of information or data on this website; the accessing or use of any information or data on this website; and/or the acts or omissions of any person or entity accessing or using any information from this website.The user hereby recognizes that the information, data, materials and related graphics are dynamic and may change over time without notice. The Department of Public Works - Engineering Services is not responsible for the use or reliance upon this information. There are links and pointers to third party internet websites contained in the City of Sacramento website. These sites linked from the City of Sacramento website are not under the City’s control. The City of Sacramento and its authorized agents and contractors do not assume any responsibility or liability for any information, communications or materials available at such linked sites, or at any link contained in a liked site. Each individual site has its own set of policies about what information is appropriate for public access. User assumes sole responsibility for use of third party links and pointers.

Benchmarks are survey markers that provide a point of particular elevation used as a reference for determining elevations of other points in a survey. They are used by surveyors, engineers, planners, and contractors for establishing elevations for planning, designing, and/or construction of various projects.The City of Portland is responsible for establishing and maintaining a network of benchmarks throughout the city, each having a known elevation expressed in feet in the City of Portland’s own datum (established in 1896). Most of the City of Portland’s Benchmarks are brass disks about 2 ½" in diameter, and all are marked "City of Portland Bench Mark No. nnnn " and usually set in the curbs of streets. Occasionally you’ll see larger disks of 3 ¾" diameter which are "Class A" monuments, and some benchmarks are set in retaining walls, bridge wing walls, culvert headwalls, concrete steps, or wherever the most stable and accessible placement was determined to be for a specific location. You might also see benchmarks similar to those of the City of Portland’s but with another governmental agency’s or private firm’s name stamped on it. Occasionally the City of Portland Benchmark Book will refer to these monuments and provide elevations, but more often you’ll have to contact the appropriate institution for more information. The benchmark numbers the City assigned to outside agency monuments are for indexing purposes only; PDOT does not stamp a City of Portland benchmark number on other agencies' monuments.-- Additional Information: Category: Survey Purpose: For mapping and analysis related to the maintenance of survey benchmarks. Update Frequency: As needed-- Metadata Link: https://www.portlandmaps.com/metadata/index.cfm?&action=DisplayLayer&LayerID=53238

A file geodatabase of survey monumentation features in Yosemite National Park, including monuments (e.g. benchmark disks), control points (e.g. rebar and cap), and destroyed or missing monuments.

This point feature class contains survey benchmark locations for The City of Pickering. Maintenance and Update Frequency: As NeededDepartment: Engineering ServicesThe City of Pickering does not make any representations concerning the accuracy, likely results or reliability of the use of the materials. The City hereby disclaims all representations and warranties. While great care will be taken to keep this information as up to date as possible we cannot guarantee complete accuracy. For additional details please refer to the most up to date version of The City of Pickering's Licence Agreement.

There are about 5,500 Geodetic Survey Control Stations in Hong Kong, including trigonometric stations, bench marks and traverse stations. The coordinates of these stations can be widely adopted for positioning tasks. The Database files (xls/xml files) contains the core information of the stations, and the Control Stations Index (kml/gml files) can be used for visualization in web maps / GIS systems. Coordinates in the Control Stations Index are approximate and should be used for reference only. Please refer to the corresponding Database files for the surveyed coordinates.

The following dataset includes "Active Benchmarks," which are provided to facilitate the identification of City-managed standard benchmarks. Standard benchmarks are for public and private use in establishing a point in space. Note: The benchmarks are referenced to the Chicago City Datum = 0.00, (CCD = 579.88 feet above mean tide New York). The City of Chicago Department of Water Management’s (DWM) Topographic Benchmark is the source of the benchmark information contained in this online database. The information contained in the index card system was compiled by scanning the original cards, then transcribing some of this information to prepare a table and map. Over time, the DWM will contract services to field verify the data and update the index card system and this online database.This dataset was last updated September 2011. Coordinates are estimated. To view map, go to https://data.cityofchicago.org/Buildings/Elevation-Benchmarks-Map/kmt9-pg57 or for PDF map, go to http://cityofchicago.org/content/dam/city/depts/water/supp_info/Benchmarks/BMMap.pdf. Please read the Terms of Use: http://www.cityofchicago.org/city/en/narr/foia/data_disclaimer.html.

The Old Erie Canal has undergone sedimentation and aquatic growth that have restricted flow and diminished the aesthetic quality of the canal during the nearly 200 years since its construction. During 2018–2019, the U.S. Geological Survey (USGS) in cooperation with the Madison County Planning Department and the New York State Canal Corporation conducted a study of the Old Erie Canal between the Town of DeWitt, New York, and its junction with the current Erie Canal of the New York State Canal System near Rome, N.Y. The study comprised bathymetric, velocity, and water-quality surveys and documentation of the canal infrastructure. The USGS established benchmarks and staff gages along the 30.8 miles of the canal study area to reference the water-surface level in the canal to the North American Vertical Datum of 1988 (NAVD 88). Water-quality data (dissolved oxygen, water temperature, specific conductance, pH, and turbidity) were collected concurrently with the bathymetric survey (spring 2018) to characterize changes in water quality along the length of the canal. The canal infrastructure was documented to provide a baseline assessment. This dataset contains a shapefile representing locations where USGS benchmarks were installed along Old Erie Canal.

Statewide dataset containing the location of geodetic control points and their associated attributes. For attribute data dictionary, see the file Geodetic-CodeGuide.doc.

This data release consists of 5390 streamflow gages within the conterminous United States that will serve as version 1.0 of streamflow benchmark locations for hydrologic model evaluation and benchmarking.

This dataset provides information about the position, position accuracy, mark name, mark type, condition and unique four letter code for geodetic marks in terms of a New Zealand's official geodetic datum.

The dataset only contains marks that are within the New Zealand mainland and offshore islands. These positions have been generated using geodetic observations such as precise differential GPS or electronic distance and theodolite angles measurements. The positions are either 2D or 3D depending of the availability of this measurement data.

The source data is from Toitū Te Whenua Land Information New Zealand's (LINZ) Landonline system where it is used by Land Surveyors. This dataset is updated daily to reflect changes made in the Landonline.

Accuracy

Geodetic marks with a coordinate order of 5 or less have been positioned in terms of NZGD2000. Lower order marks (order 6 and greater) are derived from cadastral surveys, lower accuracy measurement techniques or inaccurate historical datum transformations, and may be significantly less accurate.

The accuracy of NZGD2000 coordinates is described by a series of 'orders' classifications. Positions in terms of NZGD2000 are described by three-dimensional coordinates (latitude, longitude, ellipsoidal height). The accuracy of a survey mark is indicated by its Order. Orders are classifications based on the quality of the coordinate in relation to the datum and in relation to other surrounding marks. For more information see

Note that the accuracy applies at the time the mark was last surveyed. Refer to the web geodetic database for historical information about mark coordinates.

Note also that the existence of a mark in this dataset does not imply that there is currently a physical mark in the ground - the dataset includes destroyed or lost historical marks. The geodetic database provides more information on the mark status, valid at last time it was visited by LINZ or a maintenance contractor.

St. Johns County maintains Benchmarks throughout the County. These Benchmarks are based on closed level runs between published Benchmarks. This application shows the location of these Benchmarks along with the National Geodetic Survey (NGS) Benchmarks for St. Johns County with links to the NGS Database.

description: Points that show set benchmark or survey control locations in the City of Springfield. Many of these points are PLS section corners and quarter corners. These points have been determined and set by various agencies, organizations, and survey firms through a period of years. Attributes show who set the point.; abstract: Points that show set benchmark or survey control locations in the City of Springfield. Many of these points are PLS section corners and quarter corners. These points have been determined and set by various agencies, organizations, and survey firms through a period of years. Attributes show who set the point.

Environment Agency Control Stations (EACS) or Benchmarks (EABMs) have been created since the 1990s for use as survey control for Environment Agency projects. Control stations are fixed locations in the country which have been accurately surveyed using GPS / GNSS data. Our control stations are often near Environment Agency structures and they are used as reference heights for many different types of surveys which are carried out near the control stations. The control stations are graded with different levels of accuracy due to the varied survey techniques that were used in establishing the points.

Dauphin Island, Alabama is a barrier island located in the Gulf of Mexico that supports local residence, tourism, commercial infrastructure, and the historical Fort Gaines. During the past decade the island has been impacted by several major hurricanes (Ivan, 2004; Katrina, 2005; Isaac 2012). Storms along with sea level rise, presents a continued threat to island stability. State and federal managers are taking a scientific investigative approach to identify the best options available to formulate and implement a long-term plan to properly restore Dauphin Island and provide resilience against future storms and sea-level rise. Island morphology, including current bathymetry data, is one of several aspects being investigated and funded through a grant from National Fish and Wildlife Foundation Gulf Environmental Benefit Fund. In August 2015, the United States Geological Survey Saint Petersburg Coastal and Marine Science Center (USGS SPCMSC) in cooperation with the United States Army Corps of Engineers (USACE) and the state of Alabama conducted bathymetric surveys of the nearshore waters surrounding Dauphin Island. This data release provides 1,165-line kilometers (km) of processed single-beam bathymetry (SBB) data collected by the USGS SPCMSC in August 2015 (Field Activity Number [FAN] 2015-326-FA). Data were acquired aboard 4 separate survey vessels; the RV Sallenger (subFAN, 15BIM10), the RV Jabba Jaw (subFAN, 15BIM11), the RV Shark (subFAN, 15BIM12), and the RV Chum (subFAN, 15BIM13). The data are provided in three datums: 1) the International Terrestrial Reference Frame of 2000 (ITRF00), ellipsoid height (-47.04 meters [m] to -29.36 m); 2) the North American Datum of 1983, realization of CORS96 (NAD83 (CORS96)) horizontal, and the North American Vertical Datum 1988 (NAVD88) vertical (-0.24 m to -17.33 m); and 3) the NAD83 (CORS96) horizontal, and Mean Lower Low Water (MLLW) vertical (-0.12 m to -17.93 m). Additional files include trackline shapefiles, digital and handwritten Field Activity Collection Systems (FACS) logs, a comprehensive 50-meter Digital Elevation Model (DEM), and formal Federal Geographic Data Committee (FGDC) metadata.

This data release contains the D-score (version 0.1) daily streamflow performance benchmark results for the National Water Model (NWM) Retrospective version 2.1 computed at streamgage benchmark locations (version 1) as defined by Foks and others (2022). Model error was determined by evaluating predicted daily mean streamflow (aggregated from an hourly timestep) versus observed daily mean streamflow. Using those errors, the D-score performance benchmark computes the mean squared logarithmic error (MSLE), then decomposes the overall MSLE into orthogonal components such as bias, distribution, and sequence (Hodson and others, 2021). For easier interpretation, the MSLE components can be passed through a scoring function as described in Hodson and others (2021). References: Foks, S.S., Towler, E., Hodson, T.O., Bock, A.R., Dickinson, J.E., Dugger, A.L., Dunne, K.A., Essaid, H.I., Miles, K.A., Over, T.M., Penn, C.A., Russell, A.M., Saxe, S.W., and Simeone, C.E., 2022, Streamflow benchmark locations for conterminous United States (cobalt gages): U.S. Geological Survey data release, https://doi.org/10.5066/P972P42Z. Hodson, T.O., Over, T.M., and Foks, S.S., 2021. Mean squared error, deconstructed. Journal of Advances in Modeling Earth Systems, 13, e2021MS002681. https://doi.org/10.1029/2021MS002681.