Within the NOAA National Ocean Service (NOS), the NOAA National Geodetic Survey (NGS) has a federal mandate to provide accurate positioning, including heights, to all federal non-military mapping activities in the USA. In 2007, the NGS embarked on the Gravity for the Redefinition of the American Vertical Datum (GRAV-D) Project, one of the most ambitious projects in the history of the agency. The gravity-based vertical datum resulting from this project is accurate at the 2 cm level where possible for much of the country. Available data include airborne and terrestrial survey information, gravity data, and gravity-based geoids or datums.

Gravity for the Re-definition of the American Vertical Datum (GRAV-D) is a project initiated by NOAA's National Geodetic Survey to collect and monitor gravity data suitable for the re-definition of the vertical datum for at least the United States and territories. Airborne gravity data will be collected from 2008-2023, processed, and released periodically in geographic blocks. Each block is comprised of one or more surveys. The data will be available at https://res1geodesyd-o-tnoaad-o-tgov.vcapture.xyz/GRAV-D/data_products.shtml in ASCII text format. Some data collection has and will be done in conjunction with partners, such as the US Geological Survey, National Geospatial-Intelligence Agency, Bureau of Land Management, and the Naval Research Laboratory.

This dataset has verified (quality-controlled), daily, high low water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). This is a delayed dataset, not a near-real-time dataset.

WARNING: * Queries for data MUST include stationID=, datum=, time>=, and time<=. * Queries MUST be for less than 30 days worth of data. * Different stations support different datums. Use ERDDAP's Subset web page to find out which datums a given station supports. * The data source isn't completely reliable. If your request returns no data when you think it should: * Make sure the station you specified supports the datum you specified. * Try revising the request (e.g., a different datum or a different time range). * The list of stations offering this data (or the list of datums) may be incorrect. * Sometimes a station or the entire data service is unavailable. Wait a while and try again.

This dataset has recent, preliminary (not quality-controlled), 1-minute, water level (tide) data from NOAA NOS Center for Operational Oceanographic Products and Services (CO-OPS). WARNING: These raw data have not been subjected to the National Ocean Service's quality control or quality assurance procedures and do not meet the criteria and standards of official National Ocean Service data. They are released for limited public use as preliminary data to be used only with appropriate caution. WARNING: * Queries for data MUST include stationID=, datum=, and time>=. * Queries for data USUALLY include time<=. * Queries MUST be for less than 30 days worth of data. The default time<= value corresponds to 'now'. * Different stations support different datums. Use ERDDAP's Subset web page to find out which datums a given station supports. * The data source isn't completely reliable. If your request returns no data when you think it should: * Make sure the station you specified supports the datum you specified. * Try revising the request (e.g., a different datum or a different time range). * The list of stations offering this data (or the list of datums) may be incorrect. * Sometimes a station or the entire data service is unavailable. Wait a while and try again.

VDatum is a free software tool being developed jointly by NOAA's National Geodetic Survey (NGS), Office of Coast Survey (OCS), and Center for Operational Oceanographic Products and Services (CO-OPS). VDatum is designed to vertically transform geospatial data among a variety of tidal, orthometric and ellipsoidal vertical datums -

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, aeroplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return. Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected in 2011.An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of the DSM.This data was collected by the Office of Public Works. All data formats are provided as GeoTIFF rasters. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. OPW data has a grid cell size of 2 meter by 2 meter. This means that each cell (pixel) represents an area of 2 meter squared.

The High Resolution Digital Elevation Model (HRDEM) product is derived from airborne LiDAR data (mainly in the south) and satellite images in the north. The complete coverage of the Canadian territory is gradually being established. It includes a Digital Terrain Model (DTM), a Digital Surface Model (DSM) and other derived data. For DTM datasets, derived data available are slope, aspect, shaded relief, color relief and color shaded relief maps and for DSM datasets, derived data available are shaded relief, color relief and color shaded relief maps. The productive forest line is used to separate the northern and the southern parts of the country. This line is approximate and may change based on requirements. In the southern part of the country (south of the productive forest line), DTM and DSM datasets are generated from airborne LiDAR data. They are offered at a 1 m or 2 m resolution and projected to the UTM NAD83 (CSRS) coordinate system and the corresponding zones. The datasets at a 1 m resolution cover an area of 10 km x 10 km while datasets at a 2 m resolution cover an area of 20 km by 20 km. In the northern part of the country (north of the productive forest line), due to the low density of vegetation and infrastructure, only DSM datasets are generally generated. Most of these datasets have optical digital images as their source data. They are generated at a 2 m resolution using the Polar Stereographic North coordinate system referenced to WGS84 horizontal datum or UTM NAD83 (CSRS) coordinate system. Each dataset covers an area of 50 km by 50 km. For some locations in the north, DSM and DTM datasets can also be generated from airborne LiDAR data. In this case, these products will be generated with the same specifications as those generated from airborne LiDAR in the southern part of the country. The HRDEM product is referenced to the Canadian Geodetic Vertical Datum of 2013 (CGVD2013), which is now the reference standard for heights across Canada. Source data for HRDEM datasets is acquired through multiple projects with different partners. Since data is being acquired by project, there is no integration or edgematching done between projects. The tiles are aligned within each project. The product High Resolution Digital Elevation Model (HRDEM) is part of the CanElevation Series created in support to the National Elevation Data Strategy implemented by NRCan. Collaboration is a key factor to the success of the National Elevation Data Strategy. Refer to the “Supporting Document” section to access the list of the different partners including links to their respective data.

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.

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]).

Data consists of conversion factors that can be used to convert between numerous vertical tidal datums and the North American Vertical Datum of 1988 (NAVD88). The data cover the Eastern Shore of Virginia and parts of southeastern Maryland along with the surrounding coastal waters and are represented as approximately 100m (100.584m) resolution grids. The six included tidal datums are local mean sea level (LMSL), mean tidal level (MTL), mean low water (MLW), mean lower low water (MLLW), mean high water (MHW), and mean higher high water (MHHW). All vertical units are in meters. By combining multiple conversions to and from NAVD88, conversion between the various tidal datums is possible. Two versions of the conversion factor grids are provided for each NAVD88-to-tidal-datum pairing: one that only contains data for areas not masked as nodata by the NOAA VDatum program (original source data) and one that contains both the original and interpolated data (see below for details). Naming conventions used were "cfactor_DDD" for the original VDatum-detrived dataset where "DDD" is the local tidal datum and "cf_nd_DDD" for the dataset that includes interpolated values within the nodata masks (IDW interpolation across masked areas, typically upland regions but also shallow seaside bays and creeks for which no adequate tidal benchmarks were available). By definition, the baseline elevation (sea level or 0.0m elevation) for NAVD88 is referenced to the fixed International Great Lakes Datum of 1985 local mean sea level height value, at Rimouski, Quebec, Canada. Additional tidal bench mark elevations were not used to calculate NAVD88 due to the demonstrated variations in sea surface topography, i.e., the fact that mean sea level is not the same equipotential surface at all tidal benchmarks. The magnitude of the difference between local mean sea level (LMSL) at the tidal benchmarks of the Eastern Shore of Virginia and the NAVD88 defined sea-level varies from 0.039 to 0.149 meters BELOW zero NAVD88. Tidal prisms also vary at each tidal benchmark (in part due to differences in basin configuration and tidal interactions) causing the conversion factors for the other tidal datums to also vary spatially in similar but not identical patterns. The VDatum 3.2 software program from NOAA (http://vdatum.noaa.gov/) was used to convert the x,y,z center points of the 100m gridded data wherein all Z elevations were set equal to zero (0) from NAVD88 to each of the six local tidal datums (the X,Y horizontal WGS84 UTM 18N coordinates remained unchanged). The resulting conversion factors represent the new elevation at which the NAVD88 zero level would lie in reference to the new datum; thus, to convert from NAVD88 and the new tidal datum, one would add this conversion factor to the NAVD88 elevations to get elevations relative to the chosen tidal datum. To convert to NAVD88 from a given tidal datum, one would subtract the conversion factor from the tidal elevation. Data were turned back into gridded data with the same resolution and horizontal extent as the original data grid. The internal data grids used by the VDatum program mask as nodata most land areas (including marshes) plus many of the seaside shallow bays, either in part or in full, for which reliable tidal benchmark data is/was not available. As a result, the program cannot be used in these nodata areas, even if immediately adjacent to data areas. So as to make conversion factors available for these coastal bays and marshes and seaside watersheds of interest to the VCRLTER, conversion factors for gridded regions within the NOAA nodata masks were interpolated from neighboring data values using the inverse distance weighting (IDW) techniques employed by ESRI's ArcGIS 10.1 software. IDW interpolation resulted in conversion factors that varied gradually spatially when adjacent to the NOAA VDatum data grids but that often showed relatively sharp transitions when equidistant between different far-apart basins (such as mid-peninsula between the Chesapeake Bay and Atlantic Ocean, or within South Bay bounded by data constructed from tidal datums for the Atlantic Ocean (east), Ship Shoal Inlet (south), Sand Shoal Inlet (north), and Magothy Channel (west)). It is suggested that the appropriate use of this data is to convert elevation datasets referenced to a tidal datum to NAVD88 if integrating multiple datasets together over large areas, such as across the full Eastern Shore or across multiple watersheds or coastal bays, so as to not introduce artificial IDW-related transitions into otherwise vertically-consistent upland elevations or basin-scale bathymetric surveys. When converting elevations of fringing upland marshes, the conversion factors (including interpolated values) can likely be used directly on a cell-by-cell level to a... Visit https://dataone.org/datasets/https%3A%2F%2Fpasta.lternet.edu%2Fpackage%2Fmetadata%2Feml%2Fknb-lter-vcr%2F219%2F4 for complete metadata about this dataset.

Accurate interpretation of origination and extinction of fossil species is crucial to answering a variety of questions in paleontology. Fossil datums, the observed age of first or last occurrences, are subject to sampling error as a result of preservation and low abundances near range endpoints. This sampling error can cause local range offset, an age difference between the observed first or last occurrence of a species and its true origination or extinction. Here we develop and test a new technique, the Probable Datum Method (PDM) that can be used to assess the extent of local range offset for nannofossil species. The PDM estimates the original abundance of a taxon and its probable true age of first or last occurrence. The PDM uses a model in which original abundance is related to count abundance through preservation and the counting process. This model is empirically parameterized, including an experimental determination of false positive and error rates of a nannofossil count. ...

This dataset provides information about the number of properties, residents, and average property values for Datum Lane cross streets in Baldwinsville, NY.

Subscribers can find out export and import data of 23 countries by HS code or product’s name. This demo is helpful for market analysis.

Gravity for the Redefinition of the American Vertical Datum (GRAV-D):GRAV-D is a proposal by the National Geodetic Survey to re-define the vertical datum of the US by 2022.The gravity-based vertical datum resulting from this project will be accurate at the 2 cm level where possible for much of the country. The proposal is official policy for NGS and is included in the NGS 10 year plan. The project is currently underway and actively collecting gravity data across the United States and its holdings. It is currently "100%" complete, with all that remains being polishing up some data lines, and filling in minor gaps. The GRAV-D project consists of two major campaigns:1. A high-resolution “snapshot” of gravity in the US:This is a predominantly airborne campaign, to be accomplished around 2022 and at a cost of ~39 Million dollars. The highest priority targets are: Alaska, Puerto Rico and the Virgin Islands, the Gulf Coast, the Great Lakes, and Hawaii (some portions of which have already been completed). The coastline of the continental US and the American island holdings are also of high priority.2. A low-resolution “movie” of gravity changes:This is primarily a terrestrial campaign and will mostly encompass episodic re-visits of absolute gravity sites, attempting to monitor geographically dependent changes to gravity over time. This will allow time dependent geoid modeling and thus time dependent orthometric height monitoring through GNSS technology.The GRAV-D Data Products Map houses links to download the data from the respective block that is of interest. Only blocks that are colored green (To show completion and availability), will have a link to the data. Blocks that are colored Blue or Orange will not have a link as they are not yet ready for public download. Blue blocks represent 100% collection of data, but is still in the midst of final processing, and Orange blocks represent additional data to be collected, they will turn blue when all the data has been gathered. All data blocks will include what surveys that took part in collecting data for it, and if the block was fully completed it will list the year when it was completed.

Explore detailed Smt import data of Datum Alloys Inc in the USA—product details, price, quantity, origin countries, and US ports.

This point dataset represents the location of gaging stations in the Sacramento-San Joaquin Delta and Suisun Marsh that have historic and statistical hydrologic data, specifically various river stage data. Stages are given in NAVD88, units feet. Specific stages are given for peak stages, 100-year stages produced under 2 separate US Army Corps of Engineers hydrology reports from 1976 and 1992, the year of previous peak stages cited by the 1976 and 1992 reports, and approximate typical tidal values as approximately estimated based on long term data records. This 2023 version of this datset replaces the prior 2020 version, and should be used as a complete replacement. The underlying analyses did not change, but the USACE peak observed stage field names from the prior version were corrected and supplemental USACE 50- and 100-year stages were added accordingly. In addition, the vertical datum conversion used at specific gages was added. The vertical datum conversion is based on DWR survey and North Central Regional Office information that is maintained for each gage station. The stage data was compiled by Karen Tolentino, engineer with Delta Levees, and by Joel Dudas, Senior Engineer in DWR's Division of Engineering, based on a wide variety of sources, including the HYDSTRA database, various historic bulletins, raw data, station histories, and other information provided by DWR's North Central Region Office, USGS, and other misc sources. They also adjusted all data to approximate NAVD88-related stages. Observed data periods of record varied widely by station, but go back as far as 1905. All peak values were derived from start of records until up to May, 2017.

The associated data are considered DWR enterprise GIS data, which meet all appropriate requirements of the DWR Spatial Data Standards, specifically the DWR Spatial Data Standard version 3.5, dated April 12, 2023. DWR makes no warranties or guarantees —either expressed or implied — as to the completeness, accuracy, or correctness of the data. DWR neither accepts nor assumes liability arising from or for any incorrect, incomplete, or misleading subject data. Comments, problems, improvements, updates, or suggestions should be forwarded to GIS@water.ca.gov.

Digital Terrain Model (bare earth) of parts of Maui and Molokai. Partial coverage Vexcel, Inc. LIDAR of Maui and Molokai were purchased by County of Maui to assist with three-dimensional modeling of structures in areas of higher development. 1'/px, LIDAR-derived, bare earth DEM/elevation raster of parts of Maui and Molokai – specifically, Central Molokai, Kahului, Kihei, Lahaina and Pukalani. XY units: feet, Z units: meters. Use Limitations: 1.Disclaimer - This dataset is being placed in the public domain. Any use is allowed except for re-sale. Neither Vexcel, Inc., the County of Maui, nor the State of Hawaii make any guarantees, expressed or implied, regarding its accuracy or fitness of use. Users should verify XYZ values through a licensed surveyor for any engineering application. This data should only be used as a guide, vs. a statement of fact regarding real-world conditions. 2.Vertical Datum - The originator of this LIDAR dataset, Vexcel Inc. of Boulder, Colorado referenced Z values to the North American Vertical Datum of 1988 (NAVD88). NAVD88 is not recognized as a valid vertical reference for the state of Hawaii. Currently Hawaii has no official (de jure or de facto) vertical datum, and NOAA's National Geodetic Survey (NGS) recommends that elevations be referenced to the nearest NOAA tidal gauge. A legacy LIDAR dataset produced in 2013 by the United States Army Corps of Engineers (USACE) used NAD83(PA11) as its vertical reference. In theory this approach should result in better accuracy for the Z dimension as PA11 is a Pacific plate-centric datum. In comparing flat areas containing neither structures or vegetation, it was found that the Vexcel values sit approximately 4 feet above the USACE dataset. The vertical datum issue was brought to the attention of Vexcel, Inc. Vexcel used the 2013 USACE LIDAR as vertical control to correct their LIDAR data. The (corrected) .las data is shared as it was delivered. As stated above, the use of this data transfers all risks and assumption of responsibility to the user. For more information see https://files.hawaii.gov/dbedt/op/gis/data/Maui_2019_DTM.html or contact County of Maui at GISMonitor@co.maui.hi.us or Hawaii Statewide GIS Program at gis@hawaii.gov.

This geospatial data set depicts the locations of National Ocean Service water-level stations to determine tidal datum distributions with the Seaside, Oregon, region.

Note on Elevations: VERTICAL DATUM IS IN FEET RELATIVE TO THE INTERNATIONAL GREAT LAKES DATUM OF 1985 (IGLD85). IGLD85 ELEVATIONS CONVERSION TO NORTH AMERICAN VERTICAL DATUM OF 1988 (NAVD88) IS ELEVATION IGLD85 + 0.002 FEET = ELEVATION NAVD88. CONVERSION SOURCED FROM NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION (NOAA) ONLINE VERTICAL DATUM TRANSFORMATION TOOL. Elevation Data 1.1 2020 Coleman Wading Survey (GeoTIF) – also available as .xyz file 1.2 2020 GEI UAV Topo Survey (GeoTIF) – also available as .las file 1.3 2020 Ryba Bathymetric Survey (GeoTIF) – also available as .xyz and .shp files These files contain the elevation data that was used for the final design phase of the Marquette Lake Shore Boulevard Shoreline Restoration project. The GEI survey contains topographic information for the upland portion of the project, the Ryba survey contains bathymetric data for the nearshore, and the Coleman wading survey was conducted to survey the shoreline edge which could not be captured in the other two surveys.

Abstract: The objective is to discuss the notions of datum and analysis when the theory in question is an enunciative one, bearing in mind two central questions: if the several enunciative theories question language through a semantic point of view, aiming at studying what is singular in the speech of each speaker, how can an enunciative study be based on a corpus and, even more, constitute a database? Are enunciative studies not refractory, in a certain way, to the notion of linguistic study based on corpora? In order to answer these two questions, we present the example of a database of language disorders, ENUNSIL (Banco de Dados Enunciação e SIntoma na Linguagem), considering that, if the notion of datum is problematic to enunciative studies, such difficulties augment exponentially when symptomatic speech is at stake.