Mass Points (2008). The dataset contains DTM masspoints derived photogrammetrically to support 2’ contours. Masspoints and breaklines were compiled from Spring 2008 aerial photography using softcopy photogrammetric techniques. Masspoint elevations are in based on NAVD US feet. Masspoints and breaklines were compiled to support generation of a TIN and the subsequent processing of 2’ contours.

Source: https://carto.nationalmap.gov/arcgis/rest/services/contours/MapServerThe USGS Elevation Contours service from The National Map displays contours generated for the United States at various scales. Small-scale contours were created by USGS TNM from 1 arc-second data with 100-meter contours, and are visible at 1:600,000 and smaller scales. Medium-scale contours were created by USGS EROS from 1/3-arc-second data with 100-foot intervals, and are visible between 1:150,000 and 1:600,000. Additional medium-scale contours were created by USGS EROS from 1/3-arc-second data with 50-foot intervals, and are visible between 1:50,000 and 1:150,000. Large scale contours are updated every quarter, and are created by USGS TNM for the 7.5' 1:24,000-scale US Topo digital map series. These contours are derived from 1/3 arc-second or better resolution data, and are visible at scales 1:50,000 and larger. Large scale contour intervals are variable across the United States depending on complexity of topography, and as contours are generated per US Topo quadrangle, lines may not match across quad boundaries. The National Map download client allows free downloads of public domain contour data in either Esri File Geodatabase or Shapefile formats. The 3D Elevation Program (3DEP) provides elevation data for The National Map and basic elevation information for earth science studies and mapping applications. Scientists and resource managers use elevation data for global change research, hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. For additional information on 3DEP, go to https://www.usgs.gov/3d-elevation-program. See https://apps.nationalmap.gov/help for assistance with The National Map viewer, download client, services, or metadata.

In this joint demonstration project for the Tampa Bay region, NOAA's National Ocean Service (NOS) and the U.S. Geological Survey (USGS) have merged NOAA bathymetric and USGS topographic data sets into a hybrid digital elevation model (DEM) with all data initially referenced to the ellipsoid, but transformable to any of 28 orthometric, 3-D, or tidal datums.A seamless bathymetric/topographic digital elevation model (DEM) was developed by merging the "best available" bathymetric data from NOAA and topographic data for USGS. Each of the datasets was initially processed independently to apply the "best available" criteria to select the data to be merged. Prior to merging, the selected data were transformed to a common reference coordinate system, both horizontally and vertically.The selected topography points within the shoreline buffer zone and the bathymetry points were gridded to produce a raster surface model with a 1-arc-second (30-meter) grid spacing to match the resolution of NED. The points were input to an implementation of the ANUDEM thin plate spline interpolation algorithm, which is optimized for generation of topographic surfaces. The bathymetry points could have been gridded independently of the topographic data, but the shoreline zone land elevations were included in the interpolation to ensure a better match of the bathymetric and topographic surfaces for the subsequent mosaicing step. To avoid introduction of any interpolation edge effects into the merged elevation model, the output grid from the interpolation was clipped to include only land elevations within 300 meters of the shoreline.The final processing step involved the mosaicing of the bathymetry grid and the NED elevation grid. The values in the 300-meter overlap area were blended by weighted averaging, where the weights for each grid are determined on a cell-by-cell basis according to the cell's proximity to the edges of the overlap area. The resulting final merged product is a seamless bathymetric/topographic model covering the Tampa Bay region at a grid spacing of 1-arc-second (30-meter). The vertical coordinates represent elevation in decimal meters relative to the GRS80 ellipsoid, and the horizontal coordinates are decimal degrees of latitude and longitude referenced to the NAD83 datum.This dataset is intended for geospatial applications that require seamless land elevation and water depth information in coastal environments.

Culminating more than four years of processing data, NASA and the National Geospatial-Intelligence Agency (NGA) have completed Earth's most extensive global topographic map. The mission is a collaboration among NASA, NGA, and the German and Italian space agencies. For 11 days in February 2000, the space shuttle Endeavour conducted the Shuttle Radar Topography Mission (SRTM) using C-Band and X-Band interferometric synthetic aperture radars to acquire topographic data over 80% of the Earth's land mass, creating the first-ever near-global data set of land elevations. This data was used to produce topographic maps (digital elevation maps) 30 times as precise as the best global maps used today. The SRTM system gathered data at the rate of 40,000 per minute over land. They reveal for the first time large, detailed swaths of Earth's topography previously obscured by persistent cloudiness. The data will benefit scientists, engineers, government agencies and the public with an ever-growing array of uses. The SRTM radar system mapped Earth from 56 degrees south to 60 degrees north of the equator. The resolution of the publicly available data is three arc-seconds (1/1,200th of a degree of latitude and longitude, about 295 feet, at Earth's equator). The final data release covers Australia and New Zealand in unprecedented uniform detail. It also covers more than 1,000 islands comprising much of Polynesia and Melanesia in the South Pacific, as well as islands in the South Indian and Atlantic oceans. SRTM data are being used for applications ranging from land use planning to "virtual" Earth exploration. Currently, the mission's homepage "http://www.jpl.nasa.gov/srtm" provides direct access to recently obtained earth images. The Shuttle Radar Topography Mission C-band data for North America and South America are available to the public. A list of complete public data set is available at "http://www2.jpl.nasa.gov/srtm/dataprod.htm" The data specifications are within the following parameters: 30-meter X 30-meter spatial sampling with 16 meter absolute vertical height accuracy, 10-meter relative vertical height accuracy, and 20-meter absolute horizontal circular accuracy. From the JPL Mission Products Summary, "http://www.jpl.nasa.gov/srtm/dataprelimdescriptions.html". The primary products of the SRTM mission are the digital elevation maps of most of the Earth's surface. Visualized images of these maps are available for viewing online. Below you will find descriptions of the types of images that are being generated: Radar Image Radar Image with Color as Height Radar Image with Color Wrapped Fringes -Shaded Relief Perspective View with B/W Radar Image Overlaid Perspective View with Radar Image Overlaid, Color as Height Perspective View of Shaded Relief Perspective View with Landsat or other Image Overlaid Contour Map - B/W with Contour Lines Stereo Pair Anaglypgh The SRTM radar contained two types of antenna panels, C-band and X-band. The near-global topographic maps of Earth called Digital Elevation Models (DEMs) are made from the C-band radar data. These data were processed at the Jet Propulsion Laboratory and are being distributed through the United States Geological Survey's EROS Data Center. Data from the X-band radar are used to create slightly higher resolution DEMs but without the global coverage of the C-band radar. The SRTM X-band radar data are being processed and distributed by the German Aerospace Center, DLR.

This dataset provides a modified version of the previously published Lake Powell topobathymetric digital elevation model (TBDEM; Poppenga and others, 2020). The original TBDEM is comprised of four source datasets: (1) a 2017 1-meter multibeam bathymetric survey; (2) a 2018 topographic light detection and ranging (lidar) derived digital elevation model (DEM); (3) a historical topographic DEM that was interpolated from contours maps created in 1947 and 1959; and (4) interpolated topography where gaps existed in the bathymetric and lidar data or where historical data were not suitable (Poppenga and others, 2020). For this data release, two corrections were made to the TBDEM to address errors associated with the historic DEM and interpolated topography across data gaps: (1) filled in selected gaps of the TBDEM dataset that were corrected with the historic DEM but have since been filled with sediment; and (2) spliced alternate topographic data sources instead of the hydro-flattened ele ...

The USGS and the NGA have collaborated on the development of a notably enhanced global elevation model named the GMTED2010 that replaces GTOPO30 as the elevation dataset of choice for global and continental scale applications.

The new model has been generated at three separate resolutions (horizontal post spacings) of 30 arc-seconds (about 1 kilometer), 15 arc-seconds (about 500 meters), and 7.5 arc-seconds (about 250 meters). This new product suite provides global coverage of all land areas from lat 84°N to 56°S for most products, and coverage from 84°N to 90°S for several products. Some areas, namely Greenland and Antarctica, do not have data available at the 15- and 7.5-arc-second resolutions because the input source data do not support that level of detail. An additional advantage of the new multi-resolution global model over GTOPO30 is that seven new raster elevation products are available at each resolution.

Smoothed contours were produced at 2 foot intervals from topographic vector data (breaklines) collected by photogrammetrists. Breaklines denote the major terrain shifts as percieved by viewing the aerial photography stereoscopically. Major breaks, such as the top and bottom of hills were marked with the breaklines. Point data (DTM) was used to supplant the breakline data to provide enough information to model the terrain of the area. The data was collected at scale of 1"= 40'.

Survey field crews surveyed 14 photo identifiable points used for photo control. All the ground control points were used in the final analytical triangulation solution. The horizontal positions were reported in feet; NAD1983 (2011) Massachusetts State Plane Coordinate System, Mainland Zone, Epoch 2010.00. Elevations were based on the NorthAmerican Vertical Datum, 1988.

The aerial photographic mission was carried out on April 12, 2017. 459 exposures were taken in 16 flight lines at 3300' AMT resulting in a pixel resolution of 0.22' . The photography was collected with 60% overlap to ensure proper stereo viewing.

The digital photographs were triangulated using KLT software. The interior orientations of each photo were measured, the photos were tied togther within flight lines and lastly each flight line was tied, creating one single unified block. This block was then projected into Massachusetts State Plane NAD 83 coordinates using the14 aerial photo ground control points that were collected by traditional survey. RMS formulas were used to compute error propagation and reduce error.

The breakline and dtm data collected through the stereocompilation process was edited in KLT Atlas software to check for continuity. A TIN was generated from the edited topographic data which was then used to produce smoothed contours at 2' intervals. The contour information was then checked for errors and converted into AutoCAD .dxf format for GIS import.

This is a 1 arc-second (approximately 30 m) resolution tiled collection of the 3D Elevation Program (3DEP) seamless data products . 3DEP data serve as the elevation layer of The National Map, and provide basic elevation information for Earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for global change research, hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. 3DEP data compose an elevation dataset that consists of seamless layers and a high resolution layer. Each of these layers consists of the best available raster elevation data of the conterminous United States, Alaska, Hawaii, territorial islands, Mexico and Canada. 3DEP data are updated continually as new data become available. Seamless 3DEP data are derived from diverse source data that are processed to a common coordinate system and unit of vertical measure. These data are distributed in geographic coordinates in units of decimal degrees, and in conformance with the North American Datum of 1983 (NAD 83). All elevation values are in meters and, over the conterminous United States, are referenced to the North American Vertical Datum of 1988 (NAVD 88). The vertical reference will vary in other areas. The elevations in these DEMs represent the topographic bare-earth surface. All 3DEP products are public domain.

This dataset includes data over Canada and Mexico as part of an international, interagency collaboration with the Mexico's National Institute of Statistics and Geography (INEGI) and the Natural Resources Canada (NRCAN) Centre for Topographic Information-Sherbrook, Ottawa. For more details on the data provenance of this dataset, visit here and here.

Click here for a broad overview of this dataset

The U.S. Interagency Elevation Inventory (USIEI) displays high-accuracy topographic and bathymetric data for the United States and its territories. The project is a collaborative effort between the National Oceanic and Atmospheric Administration, the U.S. Geological Survey, the Federal Emergency Management Agency, the U.S. Department of Agriculture - Natural Resources Conservation Service and U...

A high-resolution (10-meter per pixel) digital elevation model (DEM) was created for the Sacramento-San Joaquin Delta using both bathymetry and topography data. This DEM is the result of collaborative efforts of the U.S. Geological Survey (USGS) and the California Department of Water Resources (DWR). The base of the DEM is from a 10-m DEM released in 2004 and updated in 2005 (Foxgrover and others, 2005) that used Environmental Systems Research Institute(ESRI), ArcGIS Topo to Raster module to interpolate grids from single beam bathymetric surveys collected by DWR, the Army Corp of Engineers (COE), the National Oceanic and Atmospheric Administration (NOAA), and the USGS, into a continuous surface. The Topo to Raster interpolation method was specifically designed to create hydrologically correct DEMs from point, line, and polygon data (Environmental Systems Research Institute, Inc., 2015). Elevation contour lines were digitized based on the single beam point data for control of chan ...

Elevation maps (also known as Digital Elevation Models or DEMs) of Cape Cod National Seashore were produced from remotely-sensed, geographically-referenced elevation measurements in cooperation with NASA and NPS. Point data in ascii text files were interpolated in a GIS to create a grid or digital elevation model (DEM) of each beach surface. Elevation measurements were collected in Massachusetts, over Cape Cod National Seashore using the NASA Experimental Advanced Airborne Research LiDAR (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation and coastal topography. The system uses high frequency laser beams directed at the earth's surface through an opening in the bottom of the aircraft's fuselage. The laser system records the time difference between emission of the laser beam and the reception of the reflected laser signal in the aircraft. The plane travels over the beach at approximately 60 meters per second while surveying from the low-water line to the landward base of the sand dunes. The EAARL, developed by the National Aeronautics and Space Administration (NASA) located at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 15 centimeters. A sampling rate of 3 kHz or higher results in an extremely dense spatial elevation data set. Over 100 kilometers of coastline can be easily surveyed within a 3- to 4-hour mission time period. The ability to sample large areas rapidly and accurately is especially useful in morphologically dynamic areas such as barrier beaches. Quick assessment of topographic change can be made following storms comparing measurements against baseline data. When subsequent elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding coastal development. For more information on Lidar science and the Experimental Advanced Airborne Research Lidar (EAARL) system and surveys, see http://ngom.usgs.gov/dsp/overview/index.php and http://ngom.usgs.gov/dsp/tech/eaarl/index.php .

This digital elevation model (DEM) for the Northern Atlantic Coastal Plain (NACP) from Long Island New York to northeastern North Carolina represents the elevation of the topographic and bathymetric surface at a uniform horizontal grid spacing of 100 feet and vertical units of 1 (integer) foot. The land-surface elevations are derived from U.S. Geological Survey 30-meter National Elevation Dataset (NED), and the bathymetric elevations are derived from 3 arc-second (90-meter-nominal) National Oceanic and Atmospheric Administration (NOAA) U.S. Coastal Relief Model (CRM). Horizontal coordinates are referenced to the North American Datum of 1983 (NAD 83) and vertical measurements are referenced to the North American Vertical Datum of 1988 (NAVD 88). The DEM projection is NAD_1983_Albers with linear units of US feet, a central meridian of -75.5, standard parallels of 34.5 and 41.5, and a latitude of origin of 32.

GTOPO30 is a global raster digital elevation model (DEM) providing terrain elevation data with a horizontal grid spacing of 30 arc seconds (approximately 1 kilometer). GTOPO30 was derived from several raster and vector sources of topographic information. For easier distribution, GTOPO30 has been divided into tiles [https://rda.ucar.edu/datasets/ds758.0/docs/tiles.gif]. Detailed information on the characteristics of GTOPO30 including the data distribution format, the data sources, production methods, accuracy, and hints for users, is found in the GTOPO30 README [https://rda.ucar.edu/datasets/ds758.0/docs/readme.txt] file.

GTOPO30, completed in late 1996, was developed over a three year period through a collaborative effort led by staff at the U.S. Geological Survey's Center for Earth Resources Observation and Science (EROS). The following organizations participated by contributing funding or source data: the National Aeronautics and Space Administration (NASA), the United Nations Environment Program and Global Resource Information Database (UNEP and GRID), the U.S. Agency for International Development (USAID), the Instituto Nacional de Estadistica Geografica e Informatica (INEGI) of Mexico, the Geographical Survey Institute (GSI) of Japan, Manaaki Whenua Landcare Research of New Zealand, and the Scientific Committee on Antarctic Research (SCAR).

Topographic basemap of Dedham, Massachusetts. Contours in this basemap where generated from a LiDAR based digital elevation model (DEM) with hydro enforced break lines. The LiDAR data collected as part of the 2013-14 New England CMGP SANDY LiDAR collection. Data over Dedham, MA was collected December 8th, 2013 and April 7th, 2014. The DEM was preprocessed using Esri Focal Statistics tool to generated smoother contours.Update Frequency: As NeededLast Update: 8/26/2015Additional metadata: GIS Data Dictionary

Complete Topographic dataset in shapefile format. Consume this dataset if you wish to download the entire Topographic dataset at once.

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.

A global 1-km resolution land surface digital elevation model (DEM) derived from U.S. Geological Survey (USGS) 30 arc-second SRTM30 gridded DEM data created from the NASA Shuttle Radar Topography Mission (SRTM). GTOPO30 data are used for high latitudes where SRTM data are not available. For a grayscale hillshade image layer of this dataset, see "world_srtm30plus_dem1km_hillshade" in the distribution links listed in the metadata. acknowledgement=The Pacific Islands Ocean Observing System (PacIOOS) is funded through the National Oceanic and Atmospheric Administration (NOAA) as a Regional Association within the U.S. Integrated Ocean Observing System (IOOS). PacIOOS is coordinated by the University of Hawaii School of Ocean and Earth Science and Technology (SOEST). cdm_data_type=Grid comment=These data are provided by David Sandwell of the Scripps Institution of Oceanography and subsequently distributed via THREDDS Data Server (TDS) and ERDDAP by PacIOOS. contributor2_institution=Scripps Institution of Oceanography (SIO) contributor2_name=Joseph J. Becker contributor2_role=originator contributor2_type=person contributor_email=Walter.HF.Smith@noaa.gov contributor_institution=NOAA Laboratory for Satellite Altimetry contributor_name=Walter H.F. Smith contributor_role=originator contributor_type=person contributor_url=https://www.star.nesdis.noaa.gov/star/Smith_WHF.php Conventions=CF-1.6, ACDD-1.3 date_metadata_modified=2023-01-20 drawLandMask=under Easternmost_Easting=359.99583333333334 geospatial_bounds=POLYGON ((-90 -180, 90 -180, 90 180, -90 180, -90 -180)) geospatial_bounds_crs=EPSG:4326 geospatial_lat_max=89.99583333333334 geospatial_lat_min=-89.99583333333334 geospatial_lat_resolution=0.008333333333333333 geospatial_lat_units=degrees_north geospatial_lon_max=359.99583333333334 geospatial_lon_min=0.004166666666662877 geospatial_lon_resolution=0.008333333333333333 geospatial_lon_units=degrees_east history=2015-05-20T00:00:00Z PacIOOS obtained data files from Scripps ftp then masked out the ocean data and converted to NetCDF format. id=srtm30plus_v11_land infoUrl=https://topex.ucsd.edu/WWW_html/srtm30_plus.html institution=Scripps Institution of Oceanography (SIO) instrument=Earth Remote Sensing Instruments > Active Remote Sensing > Imaging Radars > > SRTM > Shuttle Radar Topography Mission instrument_vocabulary=GCMD Instrument Keywords ISO_Topic_Categories=elevation keywords_vocabulary=GCMD Science Keywords locations=Geographic Region > Global Land locations_vocabulary=GCMD Location Keywords metadata_link=https://www.pacioos.hawaii.edu/metadata/srtm30plus_v11_land.html naming_authority=org.pacioos Northernmost_Northing=89.99583333333334 platform=Models/Analyses > > DEM > Digital Elevation Model, Space Stations/Manned Spacecraft > Space Shuttle platform_vocabulary=GCMD Platform Keywords program=Pacific Islands Ocean Observing System (PacIOOS) project=Pacific Islands Ocean Observing System (PacIOOS) references=https://www.pacioos.hawaii.edu/metadata/world_srtm30plus_dem1km_hillshade.html; Related publication: Becker, J.J., D.T. Sandwell, W.H.F. Smith, J. Braud, B. Binder, J. Depner, D. Fabre, J. Factor, S. Ingalls, S.-H. Kim, R. Ladner, K. Marks, S. Nelson, A. Pharaoh, R. Trimmer, J. Von Rosenberg, G. Wallace, and P. Weatherall (2009) Global Bathymetry and Elevation Data at 30 Arc Seconds Resolution: SRTM30_PLUS, Marine Geodesy, 32:4, 355-371, https://dx.doi.org/10.1080/01490410903297766. source=USGS SRTM30 DEM, USGS GTOPO30 DEM sourceUrl=https://pae-paha.pacioos.hawaii.edu/thredds/dodsC/srtm30plus_v11_land Southernmost_Northing=-89.99583333333334 standard_name_vocabulary=CF Standard Name Table v39 time_coverage_duration=P0D time_coverage_resolution=P0D Westernmost_Easting=0.004166666666662877

NOAA's National Centers for Environmental Information (NCEI) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support individual coastal States as part of the National Tsunami Hazard Mitigation Program's (NTHMP) efforts to improve community preparedness and hazard mitigation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources including: NOAA; the U.S. Geological Survey (USGS); and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical datum of NAVD 88 and horizontal datum of World Geodetic System 1984 geographic (WGS 84). Grid spacing for the DEM is 1/3 arc-second (~10 meters).

Dunes with a high relative topography can often be easily distinguished in high-resolution lidar-based digital elevation models (DEMs). Thus, researchers have begun using relative topography metrics, such as the topographic position index (TPI; Weiss, 2001), to identify ridges and upper slopes for extracting dunes from lidar-based DEMs (Wernette et al., 2016; Halls et al. 2018). DEMs are often used for automated delineations of intertidal and supratidal habitats in coastal applications despite issues related to vertical uncertainty. However, the level of vertical uncertainty from data collected with conventional aerial topographic lidar systems has been found to be as high as 60 cm in densely vegetated emergent wetlands throughout the United States (Medeiros et al., 2015; Buffington et al., 2016; Enwright et al., 2018). This uncertainty can also impact elevations in other habitats such as dunes due to vegetation cover and slope (Su and Bork, 2006). Another challenge when mapping g ...

The joint Natural Resources Canada/Department of Fisheries and Oceans Marine Spatial Planning Program requires the highest resolution marine based bathymetric elevation data and adjacent land based topographic elevation data that are available. This digital elevation model of Canada's west coast compiles the best data available from multiple government agencies to create a regional model gridded at 10 meter spacing. The transitions between the marine and terrestrial areas are seamless creating a continuous surface of elevations for scientific research and mapping.