This data contains a set of geodetic control stations maintained by the National Geodetic Survey in the state of Rhode Island. 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.

This dataset represents all geodetic control stations throughout the state of Rhode Island. 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.

This data is a subset of the original National Geodetic Survey (NGS) data that includes only locations within Volusia County, FL.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.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: https://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=SCALEDVertical 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,COMPUTEDLesser 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: https://www.ngs.noaa.gov/cgi-bin/ds_lookup.prl?Item=SCALEDIMPORTANT - 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 https://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 https://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 metersQuantitative_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 20850Completeness_Report:This dataset DOES NOT include destroyed marks. All other non-publishable marks are NOT included. Non-publishable criteria is available at https://www.ngs.noaa.gov/cgi-bin/craigs_lib.prl?HELP_NONPUB=1

This feature class is maintained to keep construction, mapping and all city services in and adjacent to the city on the same vertical datum. Thus minimizing mistakes or conflicts in construction or maintenance of the infrastructure of the city. This feature class represents the cities vertical control network which was started approximatley in 1971. The oringinal bench mark used to start the network was a NGS (Nationa Geodetic Survey) monument located in the northwest part of the city (Stapleton Airport/Peoria and Smith). Level loops and runs were added and extended as the city grew. Which also incorporated more NGS monuments. The datum used when the program started was NGVD (National Geodetic Vertical Datum) of 1929 . In June of 2006 the city converted from NGVD 1929 to NAVD (North American Vertical Datum) of 1988 using Corpscon 6.0.1 and the Geoid 2003. This network has been successful and should be maintained until a improved alternative can be utilized.

This point feature class contains a set of geodetic control stations maintained by the South Florida Water Management District (SFWMD). 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. This feature class is updated and maintained by SFWMD's Survey Section.

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 National Water Quality Network (NWQN) for Rivers and Streams includes 113 surface-water river and stream sites monitored by the U.S. Geological Survey (USGS) National Water Quality Program (NWQP). The NWQN represents the consolidation of four historical national networks: the USGS National Water-Quality Assessment (NAWQA) Project, the USGS National Stream Quality Accounting Network (NASQAN), the National Monitoring Network (NMN), and the Hydrologic Benchmark Network (HBN). The NWQN includes 22 large river coastal sites, 41 large river inland sites, 30 wadeable stream reference sites, 10 wadeable stream urban sites, and 10 wadeable stream agricultural sites. In addition to the 113 NWQN sites, 3 large inland river monitoring sites from the USGS Cooperative Matching Funds (Co-op) program are also included in this annual water-quality reporting Web site to be consistent with previous USGS studies of nutrient transport in the Mississippi-Atchafalaya River Basin. This data release contains geo-referenced digital data and associated attributes of watershed boundaries for 113 NWQN and 3 Co-op sites. Two sites, "Wax Lake Outlet at Calumet, LA"; 07381590, and "Lower Atchafalaya River at Morgan City, LA"; 07381600, are outflow distributaries into the Gulf of Mexico. Watershed boundaries were delineated for the portion of the watersheds between "Red River near Alexandria, LA"; 07355500 and "Atchafalaya River at Melville, LA"; 07381495 to the two distributary sites respectively. Drainage area was undetermined for these two distributary sites because the main stream channel outflows into many smaller channels so that streamflow is no longer relative to the watershed area. NWQN watershed boundaries were derived from the Watershed Boundary Dataset-12-digit hydrologic units (WBD-12). The development of the WBD-12 was a coordinated effort between the United States Department of Agriculture-Natural Resources Conservation Service (USDA-NRCS), the USGS, and the Environmental Protection Agency (EPA) (U.S. Department of Agriculture-Natural Resources Conservation Service, 2012). A hydrologic unit is a drainage area delineated to nest in a multi-level, hierarchical drainage system. Its boundaries are defined by hydrographic and topographic criteria that delineate an area of land upstream from a specific point on a river, stream or similar surface waters. The United States is divided and sub-divided into successively smaller hydrologic units identified by a unique hydrologic unit code (HUC) consisting of two to 12 digits based on the six levels of classification in the hydrologic unit system: regions, sub-regions, accounting units, cataloging units, watersheds, and sub-watersheds. NWQN watershed boundaries were delineated by selecting all sub-watershed polygons that flow into the most downstream WBD-12 polygon in which the NWQN site is located. The WBD-12 attribute table contains 8-digit, 10-digit, and 12-digit HUCs which were used to identify which sub-watersheds flow into the watershed pour point at the NWQN site location. When the NWQN site was located above the pour point of the most downstream sub-watershed, the sub-watershed was edited to make the NWQN site the pour point of that sub-watershed. To aid editing, USGS 1:24,000 digital topographic maps were used to determine the hydrologic divide from the sub-watershed boundary to the NWQN pour point. The number of sub-watersheds which are contained within the NWQN watersheds ranged from less than one to nearly 32,000 internal sub-watersheds. Internal sub-watershed boundaries were dissolved so that a single watershed boundary was generated for each NWQN watershed. Data from this release are presented at the USGS Tracking Water Quality page: http://cida.usgs.gov/quality/rivers/home (Deacon and others, 2015). Watershed boundaries delineated for this release do not take into account non-contributing area, diversions out of the watershed, or return flows into the watershed. Delineations are based solely on contributing WBD-12 polygons with modifications done only to the watershed boundary at the NWQN site location pour point. For this reason calculated drainage areas for these delineated watersheds may not match National Water Information System (MWIS) published drainage areas (http://dx.doi.org/10.5066/F7P55KJN). Deacon, J.R., Lee, C.J., Toccalino, P.L., Warren, M.P., Baker, N.T., Crawford, C.G., Gilliom, R.G., and Woodside, M.D., 2015, Tracking water-quality of the Nation’s rivers and streams, U.S. Geological Survey Web page: http://cida.usgs.gov/quality/rivers, https://dx.doi.org/doi:10.5066/F70G3H51. U.S. Department of Agriculture-Natural Resources Conservation Service, 2012, Watershed Boundary Dataset-12-digit hydrologic units: NRCS National Cartography and Geospatial Center, Fort Worth, Tex., WBDHU12_10May2012_9.3 version, accessed June 2012 at http://datagateway.nrcs.usda.gov.

As part of the Barrier Island Evolution Research Project, scientists from the U.S. Geological Survey's St. Petersburg Coastal and Marine Science Center conducted nearshore geophysical surveys off the northern Chandeleur Islands, Louisiana, in July of 2012. The overall objective of the study is to better understand barrier-island geomorphic evolution, particularly storm-related depositional and erosional processes that shape the islands over annual to interannual timescales (1-5 years). The collection of geophysical data will allow us to identify relationships between the geologic history of the island and its present day morphology and sediment distribution. This mapping effort was the first in a series of three planned surveys in this area. High resolution geophysical data collected in each of 3 consecutive years along this rapidly changing barrier-island system will provide a unique time-series dataset that will significantly further the analyses and geomorphological interpretations of this and other coastal systems, improving our understanding of coastal response and evolution over short time scales (1-5 years). This report serves as an archive of processed interferometric swath and single-beam bathymetry data that were collected during two cruises (USGS Field Activity Numbers 12BIM03 and 12BIM04) along the northern portion of the Chandeleur Islands, Breton National Wildlife Refuge, Louisiana, in July of 2012. Geographic information system data products include a 50 m-cell-size interpolated bathymetry grid surface, trackline maps, and point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.

This Web Map includes the specific locations of published tidal and NSRS bench marks in Alaska that have been prioritized for volunteer recovery with GPS for the purposes of creating an "Alaska GPS on Bench Marks" Story Map to assist Alaska-region volunteers in their field planning.Tidal bench mark priorities (2019_tide_station_BM_priorities map layer) are based on a 2019 update of Alaska tide stations where local tidal datums have been established, but have not yet been linked to the National Spatial Reference System with an OPUS Shared solution on a published tidal bench mark; submission of GPS recoveries on these marks will facilitate VDatum development in the region. Links to relevant original authoritative data are provided below:National Geodetic Survey (NGS) Integrated Database (IDB)Center for Operational Oceanographic Products and Services (CO-OPS) established tidal datums in AlaskaOnline Positioning User Service (OPUS) Shared Solutions

NGS and O'Fallon survey points. This map is intended to be a reference tool for local engineering firms, developers and surveyors.

As part of the Louisiana Coastal Protection and Restoration Authority (CPRA) Barrier Island Comprehensive Monitoring (BICM) Program, scientists from the U.S. Geological Survey (USGS) St. Petersburg Coastal and Marine Science Center conducted a single beam bathymetry survey around the Chandeleur Islands, Louisiana in June 2015. The goal of the program is to provide long-term data on Louisiana’s barrier islands and use this data to plan, design, evaluate, and maintain current and future barrier island restoration projects. The data described in this report, along with USGS bathymetry data collected in 2013 as a part of the Barrier Island Evolution Research project covering the northern Chandeleur Islands, and data collected in 2014 in collaboration with the Louisiana CPRA Barrier Island Comprehensive Monitoring project around Breton Island, will be used to assess bathymetric change since 2006-2007 and serve as a bathymetric control in supporting modeling of future changes in response to restoration and storm impacts. The survey area encompasses approximately 435 square kilometers (km2) of nearshore and back-barrier environments around Hewes Point, the Chandeleur Islands, and Curlew and Grand Gosier Shoals. This Data Series serves as an archive of processed single beam bathymetry data, collected in the nearshore of the Chandeleur Islands, Louisiana from June 17-24, 2015 during USGS Field Activity Number (FAN) 2015-317-FA. Geographic information system data products include: a 200 meter-cell-size interpolated bathymetry grid, trackline maps, and xyz point data files. Additional files include error analysis maps, Field Activity Collection System logs, and formal Federal Geographic Data Committee metadata.