[Metadatas] This layer represents the USGS topo quadrangle boundaries published in the Old Hawaiian Datum (OHD), prior to their being recast in the late 1990's. Source: Created by the Office of State Planning in the Old Hawaiian Datum using the latitude/longitude coordinates of the quadrangle boundaries, and the ARC GENERATE command.

For more information, see the full metadata at https://files.hawaii.gov/dbedt/op/gis/data/usgs_quads_ohd.pdf, or contact the 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.

[Metadata] Geoid 12B: Hybrid geoid model used to convert the ellipsoidal height obtained by the Global Navigation Satellite System (to the orthometric height of a specific vertical datum). The National Geodetic Survey (NGS) has been producing the hybrid geoid to convert the ellipsoidal height obtained from the Global Navigation Satellite System (GNSS) to the orthometric height of a specific vertical datum. The GEOID12B model is intended to transform between NAD 83 (2011/PA11/MA11) and the respective vertical datums for the different regions, including NAVD88, GUVD04, ASVD02, NMVD03, PRVD02 and VIVD09.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions in the Gulf of Mexico. These integrated bathymetric-topographic DEMs were developed for NOAA Coastal Survey Development Laboratory (CSDL) through the American Recovery and Reinvestment Act (ARRA) of 2009 to evaluate the utility of the Vertical Datum Transformation tool (VDatum), developed jointly by NOAA's Office of Coast Survey (OCS), National Geodetic Survey (NGS), and Center for Operational Oceanographic Products and Services (CO-OPS). Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. Coastal Services Center (CSC), the U.S. Office of Coast Survey (OCS), the U.S. Army Corps of Engineers (USACE), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of North American Vertical Datum of 1988 (NAVD 88), Mean High Water (MHW) or Mean Lower Low Water (MLLW) and horizontal datum of North American Datum of 1983 (NAD 83). Cell size ranges from 1/3 arc-second (~10 meters) to 1 arc-second (~30 meters). The NOAA VDatum DEM Project was funded by the American Recovery and Reinvestment Act (ARRA) of 2009 (http://www.recovery.gov/).The DEM Global Mosaic is an image service providing access to bathymetric/topographic digital elevation models stewarded at NOAA's National Centers for Environmental Information (NCEI), along with the global GEBCO_2014 grid: http://www.gebco.net/data_and_products/gridded_bathymetry_data. NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. This service is a general-purpose global, seamless bathymetry/topography mosaic. It combines DEMs from a variety of near sea-level vertical datums, such as mean high water (MHW), mean sea level (MSL), and North American Vertical Datum of 1988 (NAVD88). Elevation values have been rounded to the nearest meter, with DEM cell sizes going down to 1 arc-second. Higher-resolution DEMs, with greater elevation precision, are available in the companion NAVD88: http://noaa.maps.arcgis.com/home/item.html?id=e9ba2e7afb7d46cd878b34aa3bfce042 and MHW: http://noaa.maps.arcgis.com/home/item.html?id=3bc7611c1d904a5eaf90ecbec88fa799 mosaics. By default, the DEMs are drawn in order of cell size, with higher-resolution grids displayed on top of lower-resolution grids. If overlapping DEMs have the same resolution, the newer one is shown. Please see NCEI's corresponding DEM Footprints map service: http://noaa.maps.arcgis.com/home/item.html?id=d41f39c8a6684c54b62c8f1ab731d5ad for polygon footprints and more information about the individual DEMs used to create this composite view. In this visualization, the elevations/depths are displayed using this color ramp: http://gis.ngdc.noaa.gov/viewers/images/dem_color_scale.png.A map service showing the location and coverage of land and seafloor digital elevation models (DEMs) available from NOAA's National Centers for Environmental Information (NCEI). NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. Layers available in the map service: Layers 1-4: DEMs by Category (includes various DEMs, both hosted at NCEI, and elsewhere on the web); Layers 6-11: NCEI DEM Projects (DEMs hosted at NCEI, color-coded by project); Layer 12: All NCEI Bathymetry DEMs (All bathymetry or bathy-topo DEMs hosted at NCEI).This is an image service providing access to bathymetric/topographic digital elevation models stewarded at NOAA's National Centers for Environmental Information (NCEI), with vertical units referenced to mean high water (NAVD88). NCEI builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to understand and predict changes in Earth's environment, and conserve and manage coastal and marine resources to meet our Nation's economic, social, and environmental needs. They can be used for modeling of coastal processes (tsunami inundation, storm surge, sea-level rise, contaminant dispersal, etc.), ecosystems management and habitat research, coastal and marine spatial planning, and hazard mitigation and community preparedness. This service provides data from many individual DEMs combined together as a mosaic. By default, the rasters are drawn in order of cell size, with higher-resolution grids displayed on top of lower-resolution grids. If overlapping DEMs have the same resolution, the newer one is shown. Alternatively, a single DEM or group of DEMs can be isolated using a filter/definition query or using the 'Lock Raster 'mosaic method in ArcMap. This is one of three services displaying collections of DEMs that are referenced to common vertical datums: North American Vertical Datum of 1988 (NAVD88): http://noaa.maps.arcgis.com/home/item.html?id=e9ba2e7afb7d46cd878b34aa3bfce042, Mean High Water (MHW): http://noaa.maps.arcgis.com/home/item.html?id=3bc7611c1d904a5eaf90ecbec88fa799, and Mean Higher High Water: http://noaa.maps.arcgis.com/home/item.html?id=9471f8d4f43e48109de6275522856696. In addition, the DEM Global Mosaic is a general-purpose global, seamless bathymetry/topography mosaic containing all the DEMs together. Two services are available: http://noaa.maps.arcgis.com/home/item.html?id=c876e3c96a8642ab8557646a3b4fa0ff Elevation Values: http://noaa.maps.arcgis.com/home/item.html?id=c876e3c96a8642ab8557646a3b4fa0ff and Color Shaded Relief: http://noaa.maps.arcgis.com/home/item.html?id=feb3c625dc094112bb5281c17679c769. Please see the corresponding DEM Footprints map service: http://noaa.maps.arcgis.com/home/item.html?id=d41f39c8a6684c54b62c8f1ab731d5ad for polygon footprints and more information about the individual DEMs used to create this composite view. This service has several server-side functions available. These can be selected in the ArcGIS Online layer using 'Image Display ', or in ArcMap under 'Processing Templates '. None: The default. Provides elevation/depth values in meters relative to the NAVD88 vertical datum. ColorHillshade: An elevation-tinted hillshade visualization. The depths are displayed using this color ramp: http://gis.ngdc.noaa.gov/viewers/images/dem_color_scale.png. GrayscaleHillshade: A simple grayscale hillshade visualization. SlopeMapRGB: Slope in degrees, visualized using these colors: http://downloads.esri.com/esri_content_doc/landscape/SlopeMapLegend_V7b.png. SlopeNumericValues: Slope in degrees, returning the actual numeric values. AspectMapRGB: Orientation of the terrain (0-360 degrees), visualized using these colors: http://downloads.esri.com/esri_content_doc/landscape/AspectMapLegendPie_V7b.png. AspectNumericValues: Aspect in degrees, returning the actual numeric values.

Tidal Datum GIS outputsShapefiles are provided that present the approximate shore-parallel extent of tidal datums across coastal Massachusetts. These shapefiles are provided for 2030, 2050, and 2070 sea level rise scenarios. Individual shapefiles are provided for the north and south model domains for a total of 6 tidal datum shapefiles (2 model domains, 3 sea level rise scenarios). The results presented within these polygons are based upon tidal model simulations conducted using the MC-FRM, with north shapefiles created using the north model domain, and south using the south model domain. Separate polygons (zones) are provided for approximate location where MHW values vary to the nearest 0.1 ft interval. These zones are derived based on the variation in the MHW datum, and as such other datums (MHHW, MTL, MLW, and MLLW) may vary withineach segmented polygon, especially in areas of varied bathymetry. Data are presented in units of feet relative to the NAVD88 datum.These shapefiles contain the following fields: FID, Shape, Hatch, MHHW, MHW, MTL, MLW, and MLLW. The MHHW, MHW, MTL, MLW, and MLLW fields contain float type values representing the tidal datums calculated for each polygon rounded to the nearest tenth of a foot. The Hatch field contains a binary value (0 or 1), with 1 representing zones of uncertainty for tidal datums. These uncertain zones are either dynamic in terms of geomorphology or are restricted by smaller anthropogenic features (culverts, tide gates, etc.) that were not fully resolved in the MC-FRM. Zones with a 1 Hatch value may or may not contain tidal datum information. It is recommended that care be taken when utilizing the tidal benchmark information in these hatched zones and site-specific data observations (tide data) are recommended to verify the values in these areas. If datum information is not available 9999 values are located in the datum fields for that polygon. The FID and Shape fields contain an ID number and shape type contained in each polygon.The shapefiles provided are not intended to represent a spatial extent of the tidal benchmark (i.e., they do not present the geospatial location of water level). Rather, these shapefiles provide the tidal benchmark values that should be applied over each of the geospatial zones.

USGS is assessing the feasibility of map projections and grid systems for lunar surface operations. We propose developing a new Lunar Transverse Mercator (LTM), the Lunar Polar Stereographic (LPS), and the Lunar Grid Reference Systems (LGRS). We have also designed additional grids designed to NASA requirements for astronaut navigation, referred to as LGRS in Artemis Condensed Coordinates (ACC), but this is not released here. LTM, LPS, and LGRS are similar in design and use to the Universal Transverse Mercator (UTM), Universal Polar Stereographic (LPS), and Military Grid Reference System (MGRS), but adhere to NASA requirements. LGRS ACC format is similar in design and structure to historic Army Mapping Service Apollo orthotopophoto charts for navigation. The Lunar Transverse Mercator (LTM) projection system is a globalized set of lunar map projections that divides the Moon into zones to provide a uniform coordinate system for accurate spatial representation. It uses a transverse Mercator projection, which maps the Moon into 45 transverse Mercator strips, each 8°, longitude, wide. These transverse Mercator strips are subdivided at the lunar equator for a total of 90 zones. Forty-five in the northern hemisphere and forty-five in the south. LTM specifies a topocentric, rectangular, coordinate system (easting and northing coordinates) for spatial referencing. This projection is commonly used in GIS and surveying for its ability to represent large areas with high positional accuracy while maintaining consistent scale. The Lunar Polar Stereographic (LPS) projection system contains projection specifications for the Moon’s polar regions. It uses a polar stereographic projection, which maps the polar regions onto an azimuthal plane. The LPS system contains 2 zones, each zone is located at the northern and southern poles and is referred to as the LPS northern or LPS southern zone. LPS, like is equatorial counterpart LTM, specifies a topocentric, rectangular, coordinate system (easting and northing coordinates) for spatial referencing. This projection is commonly used in GIS and surveying for its ability to represent large polar areas with high positional accuracy, while maintaining consistent scale across the map region. LGRS is a globalized grid system for lunar navigation supported by the LTM and LPS projections. LGRS provides an alphanumeric grid coordinate structure for both the LTM and LPS systems. This labeling structure is utilized in a similar manner to MGRS. LGRS defines a global area grid based on latitude and longitude and a 25×25 km grid based on LTM and LPS coordinate values. Two implementations of LGRS are used as polar areas require a LPS projection and equatorial areas a transverse Mercator. We describe the difference in the techniques and methods report associated with this data release. Request McClernan et. al. (in-press) for more information. ACC is a method of simplifying LGRS coordinates and is similar in use to the Army Mapping Service Apollo orthotopophoto charts for navigation. These data will be released at a later date. Two versions of the shape files are provided in this data release, PCRS and Display only. See LTM_LPS_LGRS_Shapefiles.zip file. PCRS are limited to a single zone and are projected in either LTM or LPS with topocentric coordinates formatted in Eastings and Northings. Display only shapefiles are formatted in lunar planetocentric latitude and longitude, a Mercator or Equirectangular projection is best for these grids. A description of each grid is provided below: Equatorial (Display Only) Grids: Lunar Transverse Mercator (LTM) Grids: LTM zone borders for each LTM zone Merged LTM zone borders Lunar Polar Stereographic (LPS) Grids: North LPS zone border South LPS zone border Lunar Grid Reference System (LGRS) Grids: Global Areas for North and South LPS zones Merged Global Areas (8°×8° and 8°×10° extended area) for all LTM zones Merged 25km grid for all LTM zones PCRS Shapefiles:` Lunar Transverse Mercator (LTM) Grids: LTM zone borders for each LTM zone Lunar Polar Stereographic (LPS) Grids: North LPS zone border South LPS zone border Lunar Grid Reference System (LGRS) Grids: Global Areas for North and South LPS zones 25km Gird for North and South LPS zones Global Areas (8°×8° and 8°×10° extended area) for each LTM zone 25km grid for each LTM zone The rasters in this data release detail the linear distortions associated with the LTM and LPS system projections. For these products, we utilize the same definitions of distortion as the U.S. State Plane Coordinate System. Scale Factor, k - The scale factor is a ratio that communicates the difference in distances when measured on a map and the distance reported on the reference surface. Symbolically this is the ratio between the maps grid distance and distance on the lunar reference sphere. This value can be precisely calculated and is provided in their defining publication. See Snyder (1987) for derivation of the LPS scale factor. This scale factor is unitless and typically increases from the central scale factor k_0, a projection-defining parameter. For each LPS projection. Request McClernan et. al., (in-press) for more information. Scale Error, (k-1) - Scale-Error, is simply the scale factor differenced from 1. Is a unitless positive or negative value from 0 that is used to express the scale factor’s impact on position values on a map. Distance on the reference surface are expended when (k-1) is positive and contracted when (k-1) is negative. Height Factor, h_F - The Height Factor is used to correct for the difference in distance caused between the lunar surface curvature expressed at different elevations. It is expressed as a ratio between the radius of the lunar reference sphere and elevations measured from the center of the reference sphere. For this work, we utilized a radial distance of 1,737,400 m as recommended by the IAU working group of Rotational Elements (Archinal et. al., 2008). For this calculation, height factor values were derived from a LOLA DEM 118 m v1, Digital Elevation Model (LOLA Science Team, 2021). Combined Factor, C_F – The combined factor is utilized to “Scale-To-Ground” and is used to adjust the distance expressed on the map surface and convert to the position on the actual ground surface. This value is the product of the map scale factor and the height factor, ensuring the positioning measurements can be correctly placed on a map and on the ground. The combined factor is similar to linear distortion in that it is evaluated at the ground, but, as discussed in the next section, differs numerically. Often C_F is scrutinized for map projection optimization. Linear distortion, δ - In keeping with the design definitions of SPCS2022 (Dennis 2023), we refer to scale error when discussing the lunar reference sphere and linear distortion, δ, when discussing the topographic surface. Linear distortion is calculated using C_F simply by subtracting 1. Distances are expended on the topographic surface when δ is positive and compressed when δ is negative. The relevant files associated with the expressed LTM distortion are as follows. The scale factor for the 90 LTM projections: LUNAR_LTM_GLOBAL_PLOT_HEMISPHERES_distortion_K_grid_scale_factor.tif Height Factor for the LTM portion of the Moon: LUNAR_LTM_GLOBAL_PLOT_HEMISPHERES_distortion_EF_elevation_factor.tif Combined Factor in LTM portion of the Moon LUNAR_LTM_GLOBAL_PLOT_HEMISPHERES_distortion_CF_combined_factor.tif The relevant files associated with the expressed LPS distortion are as follows. Lunar North Pole The scale factor for the northern LPS zone: LUNAR_LGRS_NP_PLOT_LPS_K_grid_scale_factor.tif Height Factor for the north pole of the Moon: LUNAR_LGRS_NP_PLOT_LPS_EF_elevation_factor.tif Combined Factor for northern LPS zone: LUNAR_LGRS_NP_PLOT_LPS_CF_combined_factor.tif Lunar South Pole Scale factor for the northern LPS zone: LUNAR_LGRS_SP_PLOT_LPS_K_grid_scale_factor.tif Height Factor for the south pole of the Moon: LUNAR_LGRS_SP_PLOT_LPS_EF_elevation_factor.tif Combined Factor for northern LPS zone: LUNAR_LGRS_SP_PLOT_LPS_CF_combined_factor.tif For GIS utilization of grid shapefiles projected in Lunar Latitude and Longitude, referred to as “Display Only”, please utilize a registered lunar geographic coordinate system (GCS) such as IAU_2015:30100 or ESRI:104903. LTM, LPS, and LGRS PCRS shapefiles utilize either a custom transverse Mercator or polar Stereographic projection. For PCRS grids the LTM and LPS projections are recommended for all LTM, LPS, and LGRS grid sizes. See McClernan et. al. (in-press) for such projections. Raster data was calculated using planetocentric latitude and longitude. A LTM and LPS projection or a registered lunar GCS may be utilized to display this data. Note: All data, shapefiles and rasters, require a specific projection and datum. The projection is recommended as LTM and LPS or, when needed, IAU_2015:30100 or ESRI:104903. The datum utilized must be the Jet Propulsion Laboratory (JPL) Development Ephemeris (DE) 421 in the Mean Earth (ME) Principal Axis Orientation as recommended by the International Astronomy Union (IAU) (Archinal et. al., 2008).

This downloadable zip file contains an ESRI File Geodatabase that is compatible with most versions of ArcGIS Pro, ArcMap, and AutoCAD Map 3D or Civil 3D. To view the geodatabase’s contents, please download the zip file to a local directory and extract its contents. This zipped geodatabase will require approximately 1.57 GB of disc space (1.73 GB extracted). Due to its size, the zip file may take some time to download.The geodatabase in the download includes the following layers:2 foot contours, Spot Elevations, Breaklines2015 LiDAR derived 2ft topographic contours for Tallahassee and Leon County, Florida. Topographic contours re-projected from NAD83 State Plane to Web Mercator. Source data vertical datum NAVD88.TLCGIS regularly uses digital orthophotos and planimetric/hydrographic/topographic data to support regulatory functions, land management and acquisition, planning, engineering and habitat restoration projects.This dataset is part of a regularly scheduled update of LiDAR and digital orthophotography products. The dataset was created from source imagery acquired by a Trimble TAC80 natural color digital camera and LAS data acquired by a Optech ALTM HA500 (Pegasus) LIDAR sensor from January 18, 2015 to February 5, 2015.

This study is the first comprehensive publication of tidal datums and extreme tides for San Francisco Bay (Bay) since the United States Army Corps of Engineers (USACE) published itsSan Francisco Bay Tidal Stage vs. Frequency Study in 1984 (USACE 1984). The USACE study was groundbreaking at the time of publication, presenting tidal datums and the “100-year tide” elevation for 53 locations around the Bay. The purpose of this study is to update and expand on the USACE study and to present daily and extreme tidal information for more than 900 locations along the Bay shoreline. Tidal datums, described further in Section 2 , are standard elevations defined by a certain phase of the tide (e.g., mean high tide, mean low tide). A tidal datum is used as a reference to measure and define local water levels, and as such is specific to local hydrodynamic processes and is not easily extended from one area to another without substantiating measurements or analysis. Many industries and activities rely on tidal datums, including shipping and navigation, coastal flood management, coastal development, and wetland restoration. Extreme tidal elevations are estimated for less-frequent extreme tides (e.g., 2-year tides to 500-year tides [tides with a 50.0 percent to 0.2 percent annual chance of occurrence, respectively]). Knowledge of the 100-year tide, or the water elevation with a 1 percent annual chance of occurrence, is critical for shoreline planning, floodplain management, and sea level rise (SLR) adaptation efforts. This study presents detailed daily and extreme tide information for the entirety of the Bay shoreline. This data set will support floodplain management efforts; shoreline vulnerability and risk analyses; shoreline engineering, design, and permitting; ecological studies; and appropriate sea level rise adaptation planning. The goal of this study is to provide data that support a wide-range of planning efforts around the Bay, particularly as communities seek to understand—and begin to adapt to—rising sea levels. You can access the full report at: http://www.adaptingtorisingtides.org/wp-content/uploads/2016/05/20160429.SFBay_Tidal-Datums_and_Extreme_Tides_Study.FINAL_.pdf.

U.S. State Plane Zones (NAD 1983) represents the State Plane Coordinate System (SPCS) Zones for the 1983 North American Datum within United States.

The Christmas Island Geographic Information System (CIGIS) is a collection of spatial data, viewing and analysis tools dealing with Christmas Island, Indian Ocean. The data include orthophotography, topographic, mining, cultural and environmental features of the island. This work is part of ongoing service to the Department of Transport and Regional Services.

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 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.

Tidal Datum GIS outputsShapefiles are provided that present the approximate shore-parallel extent of tidal datums across coastal Massachusetts. These shapefiles are provided for 2030, 2050, and 2070 sea level rise scenarios. Individual shapefiles are provided for the north and south model domains for a total of 6 tidal datum shapefiles (2 model domains, 3 sea level rise scenarios). The results presented within these polygons are based upon tidal model simulations conducted using the MC-FRM, with north shapefiles created using the north model domain, and south using the south model domain. Separate polygons (zones) are provided for approximate location where MHW values vary to the nearest 0.1 ft interval. These zones are derived based on the variation in the MHW datum, and as such other datums (MHHW, MTL, MLW, and MLLW) may vary withineach segmented polygon, especially in areas of varied bathymetry. Data are presented in units of feet relative to the NAVD88 datum.These shapefiles contain the following fields: FID, Shape, Hatch, MHHW, MHW, MTL, MLW, and MLLW. The MHHW, MHW, MTL, MLW, and MLLW fields contain float type values representing the tidal datums calculated for each polygon rounded to the nearest tenth of a foot. The Hatch field contains a binary value (0 or 1), with 1 representing zones of uncertainty for tidal datums. These uncertain zones are either dynamic in terms of geomorphology or are restricted by smaller anthropogenic features (culverts, tide gates, etc.) that were not fully resolved in the MC-FRM. Zones with a 1 Hatch value may or may not contain tidal datum information. It is recommended that care be taken when utilizing the tidal benchmark information in these hatched zones and site-specific data observations (tide data) are recommended to verify the values in these areas. If datum information is not available 9999 values are located in the datum fields for that polygon. The FID and Shape fields contain an ID number and shape type contained in each polygon.The shapefiles provided are not intended to represent a spatial extent of the tidal benchmark (i.e., they do not present the geospatial location of water level). Rather, these shapefiles provide the tidal benchmark values that should be applied over each of the geospatial zones.

In surveying, benchmarks represent points of reference for measurement. This layer shows benchmark points for all of Orange County. It includes the northing, easting and elevation for each point. A detailed description on relative location is also included. Orange County Public Works Survey.

This map represents City of Salem, Oregon, Survey Benchmarks. The Survey Section of the Public Works Department establishes and maintains horizontal and vertical survey control throughout the City for most public and private projects. Vertical datum is NGVD 1929-47. Horizontal datum is NAD 1983-91. The map references detailed GIS data provided by the City of Salem Public Works Department. Contact the City of Salem City Surveyor (503-588-6211) for questions and the most up-to-date information, or gis@cityofsalem.net.

Tidal Datum GIS outputsShapefiles are provided that present the approximate shore-parallel extent of tidal datums across coastal Massachusetts. These shapefiles are provided for 2030, 2050, and 2070 sea level rise scenarios. Individual shapefiles are provided for the north and south model domains for a total of 6 tidal datum shapefiles (2 model domains, 3 sea level rise scenarios). The results presented within these polygons are based upon tidal model simulations conducted using the MC-FRM, with north shapefiles created using the north model domain, and south using the south model domain. Separate polygons (zones) are provided for approximate location where MHW values vary to the nearest 0.1 ft interval. These zones are derived based on the variation in the MHW datum, and as such other datums (MHHW, MTL, MLW, and MLLW) may vary withineach segmented polygon, especially in areas of varied bathymetry. Data are presented in units of feet relative to the NAVD88 datum.These shapefiles contain the following fields: FID, Shape, Hatch, MHHW, MHW, MTL, MLW, and MLLW. The MHHW, MHW, MTL, MLW, and MLLW fields contain float type values representing the tidal datums calculated for each polygon rounded to the nearest tenth of a foot. The Hatch field contains a binary value (0 or 1), with 1 representing zones of uncertainty for tidal datums. These uncertain zones are either dynamic in terms of geomorphology or are restricted by smaller anthropogenic features (culverts, tide gates, etc.) that were not fully resolved in the MC-FRM. Zones with a 1 Hatch value may or may not contain tidal datum information. It is recommended that care be taken when utilizing the tidal benchmark information in these hatched zones and site-specific data observations (tide data) are recommended to verify the values in these areas. If datum information is not available 9999 values are located in the datum fields for that polygon. The FID and Shape fields contain an ID number and shape type contained in each polygon.The shapefiles provided are not intended to represent a spatial extent of the tidal benchmark (i.e., they do not present the geospatial location of water level). Rather, these shapefiles provide the tidal benchmark values that should be applied over each of the geospatial zones.

The files linked to this reference are the geospatial data created as part of the completion of the baseline vegetation inventory project for the NPS park unit. Current format is ArcGIS file geodatabase but older formats may exist as shapefiles. We converted the photointerpreted data into a GIS-usable format employing three fundamental processes: (1) orthorectify, (2) digitize, and (3) develop the geodatabase. All digital map automation was projected in Universal Transverse Mercator (UTM) projection, Zone 16, using North American Datum of 1983 (NAD83). To produce a polygon vector layer for use in ArcGIS, we converted each raster-based image mosaic of orthorectified overlays containing the photointerpreted data into a grid format using ArcGIS (Version 9.2, © 2006 Environmental Systems Research Institute, Redlands, California). In ArcGIS, we used the ArcScan extension to trace the raster data and produce ESRI shapefiles. We digitally assigned map attribute codes (both map class codes and physiognomic modifier codes) to the polygons, and checked the digital data against the photointerpreted overlays for line and attribute consistency. Ultimately, we merged the individual layers into a seamless layer of INDU and immediate environs. At this stage, the map layer has only map attribute codes assigned to each polygon. To assign meaningful information to each polygon (e.g., map class names, physiognomic definitions, link to NVC association and alliance codes), we produced a feature class table along with other supportive tables and subsequently related them together via an ArcGIS Geodatabase. This geodatabase also links the map to other feature class layers produced from this project, including vegetation sample plots, accuracy assessment sites, and project boundary extent. A geodatabase provides access to a variety of interlocking data sets, is expandable, and equips resource managers and researchers with a powerful GIS tool.

The U.S. Geological Survey (USGS) has compiled national shoreline data for more than 20 years to document coastal change and serve the needs of research, management, and the public. Maintaining a record of historical shoreline positions is an effective method to monitor national shoreline evolution over time, enabling scientists to identify areas most susceptible to erosion or accretion. These data can help coastal managers and planners understand which areas of the coast are vulnerable to change. This data release includes a compilation of previously published historical shoreline positions for Virginia spanning 148 years (1849-1997), and two new mean high water (MHW) shorelines extracted from lidar data collected in 2010 and 2017. These data provide a standardized shoreline database for the state. This release includes both long-term (up to 168 years) and short term (~20 years) rates. Files associated with the long-term and short-term rates are appended with "LT" and "ST", respectively. A proxy-datum bias reference line that accounts for the positional difference in a proxy shoreline (e.g. High Water Line (HWL) shoreline) and a datum shoreline (e.g. MHW shoreline) is also included in this release.

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.

US Geologic Service (USGS) Digital Raster Graphics (1:24000 scale) for the State of Georgia, combined with a hillshade visualization of a 10 meter Digital Elevation Model (DEM). A DRG is an image of a USGS standard series topographic map scanned at a minimum resolution of 250 dots per inch, and georeferenced to the Universal Transverse Mercator (UTM) projection. Each 7.5-minute DRG provides coverage for an area of land measuring 7.5-minutes of latitude by 7.5-minutes longitude. The horizontal positional accuracy and datum of the DRG matches that of the source map. The National Elevation Dataset (NED) is produced and distributed by the USGS. The NED is derived from diverse sources and processed to a common coordinate system and unit of vertical measure. NED data are in geographic coordinates (decimal degree units) and conform with the North American Datum of 1983. Elevation values are in meters, and referenced to the North American Vertical Datum of 1988 over the conterminous US. Although these data have been processed successfully on a computer system at the Georgia GIS Data Clearinghouse, no warranty expressed or implied is made by Georgia GIS Data Clearinghouse regarding the utility of the data on any other system, nor shall the act of distribution constitute any such warranty.