Digital elevation model (DEM) data are arrays of regularly spaced elevation values referenced horizontally either to a Universal Transverse Mercator (UTM) projection or to a geographic coordinate system. The grid cells are spaced at regular intervals along south to north profiles that are ordered from west to east. The U.S. Geological Survey (USGS) produces five primary types of elevation data: 7.5-minute DEM, 30-minute DEM, 1-degree DEM.These datasets were derived from USGS 7.5' DEM Quads for the main 8 Hawaiian Islands. Individual DEM quads were converted to a common datum, and vertical unit, and subsequently mosaicked in ArcGIS 9.x. The DEM for Hawaii (Big Island) has a coordinate system of NAD83 UTM5N. The DEM for the remaining 7 islands (Maui, Kahoolawe, Lanai, Molokai, Oahu, Kauai and Niihau) have a coordinate system of NAD83 UTM4N. All rasters have a spatial resolution of 10 meters and are in the ESRI grid format. On this metadata sheet, the bounding coordinates and row and column counts are for a hypothetical 10m grid that would contain the 8 main Hawaiian Islands. For bounding coordinates and the number of rows and columns for each actual, individual DEM, users should consult their respective layer properties.

These topographic/bathymetric digital elevation models (DEMs) were collected and compiled to characterize erosion and deposition in the Colorado River and in an adjacent zone of laterally recirculating flow (eddy) during both average flow conditions and during a controlled flood that occurred in March 2008. The objectives of the study were to measure changes sandbar morphology that occurred during changes in discharge associated with the controlled flood. These data were collected between February 6 and March 31, 2008 in a 1-mile study reach on the Colorado River within Grand Canyon National Park beginning 44.5 miles downstream from Lees Ferry, Arizona. These data were collected by the USGS Grand Canyon Monitoring and Research Center with cooperators from Northern Arizona University and funding provided by the Glen Canyon Dam Adaptive Management Program. All bathymetric data were collected with a multibeam sonar system (Reson Seabat 8124 sonar with TSS MAHRSS reference system for heave, pitch, roll, and heading). Topographic data were collected by conventional total station. These data can be used to study changes in channel morphology associated with changes in streamflow conditions.

A 10-meter resolution land surface digital elevation model (DEM) for the islands of Palau from U.S. Geological Survey (USGS) 1/3 arc-second DEM quadrangles. For a grayscale hillshade image layer of this dataset, see "pw_usgs_all_dem10m_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 USGS and subsequently distributed via THREDDS Data Server (TDS) and ERDDAP by PacIOOS. Conventions=CF-1.6, ACDD-1.3 date_metadata_modified=2023-01-20 drawLandMask=off Easternmost_Easting=134.64967501368815 geospatial_bounds=POLYGON ((6.874626 134.096848, 7.754260 134.096848, 7.754260 134.693147, 6.874626 134.693147, 6.874626 134.096848)) geospatial_bounds_crs=EPSG:4326 geospatial_lat_max=7.754213715821437 geospatial_lat_min=6.874765028140425 geospatial_lat_resolution=9.25930393431261E-5 geospatial_lat_units=degrees_north geospatial_lon_max=134.64967501368815 geospatial_lon_min=134.09689456880972 geospatial_lon_resolution=9.259303934312171E-5 geospatial_lon_units=degrees_east history=2015-05-11T00:00:00Z PacIOOS obtained ArcInfo Binary Grids from The National Map Viewer of USGS then mosaicked and converted to NetCDF format and EPSG:4326 spatial reference system. id=usgs_dem_10m_palau infoUrl=https://www.usgs.gov/core-science-systems/national-geospatial-program/national-map institution=U.S. Geological Survey (USGS) instrument=Not Applicable > Not Applicable instrument_vocabulary=GCMD Instrument Keywords ISO_Topic_Categories=elevation keywords_vocabulary=GCMD Science Keywords locations=Ocean > Pacific Ocean > Western Pacific Ocean > Micronesia > Palau locations_vocabulary=GCMD Location Keywords metadata_link=https://www.pacioos.hawaii.edu/metadata/usgs_dem_10m_palau.html naming_authority=org.pacioos Northernmost_Northing=7.754213715821437 platform=Models/Analyses > > DEM > Digital Elevation Model 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/pw_usgs_all_dem10m_hillshade.html source=USGS 1/3 arc-second DEM quadrangles sourceUrl=https://pae-paha.pacioos.hawaii.edu/thredds/dodsC/usgs_dem_10m_palau Southernmost_Northing=6.874765028140425 standard_name_vocabulary=CF Standard Name Table v39 time_coverage_duration=P0D time_coverage_resolution=P0D Westernmost_Easting=134.09689456880972

The GEODATA 9 Second Digital Elevation Model (DEM-9S) Version 3 is a grid of ground level elevation points covering the whole of Australia with a grid spacing of 9 seconds in longitude and latitude (approximately 250 metres) in the GDA94 coordinate system.

Version 3 of the DEM-9S was calculated by Version 5.2.2 of the ANUDEM procedure (Hutchinson 2007) from comprehensively revised and augmented national GEODATA-250K topographic source data (AUSLIG 1992, Geoscience Australia 2003, Geoscience Australia 2006) using Version 5.2.2 of the ANUDEM elevation gridding procedure. The source data included revised versions of GEODATA-250K elevation points, streamlines, cliff lines and waterbodies, trigonometric points from the National Geodetic Database and additional elevation and sink point data digitised by the Fenner School from 1:100K source material. Version 5.2.2 of the ANUDEM procedure incorporates major upgrades to the modelling of streamlines, lakes, cliff lines and the coastline.

GEODATA 9 Second Flow Direction Grid (D8-9S) has been released for the first time with Version 3. The D8-9S is a corresponding grid describing the principal directions of surface drainage across the whole of Australia. This grid was calculated by the ANUDEM procedure as it derived the DEM-9S. It incorporates the data streamline structure and describes the drainage structure continent-wide. It can be used to delineate streamlines and associated catchment boundaries for the DEM-9S. This is particularly useful in low relief areas where drainage structure is not reliably defined by the DEM-9S elevations alone.

The product can be used for applications requiring accurate representation of absolute elevation values. The elevation of source data high points (hills or mountains) is well represented in Version 3. The 1:250,000 source scale of the elevation grid makes the product useful for national, State-wide and regional applications.

For more detailed information please refer to the User Guide below.

Product Information

Coverage: Australia, excluding external territories

Currency: 2008

Coordinates: Geographical

Datum: Horizontal: GDA94; Vertical: AHD71

Available Formats: GeoTIFF

This dataset contains the Digital Elevation Model (DEM) for Europe from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The data were developed and distributed by processing units. There are 11 processing units for Europe. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. eu_dem_3_2.zip contains the DEM data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

A seamless, 2 meter resolution digital elevation model (DEM) was constructed for the open-coast region of the San Francisco Bay Area (outside of the Golden Gate Bridge), extending from Half Moon Bay to Bodega Head along the north-central California coastline. The goal was to integrate the most recent high-resolution bathymetric and topographic datasets available (for example, Light Detection and Ranging (lidar) topography, multibeam and single-beam sonar bathymetry) into a seamless surface model extending offshore at least 3 nautical miles and inland beyond the +20 m elevation contour.

NOAA's National Geophysical Data Center (NGDC) is building high-resolution digital elevation models (DEMs) for select U.S. coastal regions. These integrated bathymetric-topographic DEMs are used to support tsunami forecasting and warning efforts at the NOAA Center for Tsunami Research, Pacific Marine Environmental Laboratory (PMEL). The DEMs are part of the tsunami forecast system SIFT (Short-term Inundation Forecasting for Tsunamis) currently being developed by PMEL for the NOAA Tsunami Warning Centers, and are used in the MOST (Method of Splitting Tsunami) model developed by PMEL to simulate tsunami generation, propagation, and inundation. Bathymetric, topographic, and shoreline data used in DEM compilation are obtained from various sources, including NGDC, the U.S. National Ocean Service (NOS), the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), the Federal Emergency Management Agency (FEMA), and other federal, state, and local government agencies, academic institutions, and private companies. DEMs are referenced to the vertical tidal datum of Mean High Water (MHW) and horizontal datum of World Geodetic System 1984 (WGS84). Grid spacings for the DEMs range from 1/3 arc-second (~10 meters) to 3 arc-seconds (~90 meters).

This dataset provides an updated digital elevation model (DEM) for the Atchafalaya and Terrebonne basins in coastal Louisiana, USA. The DEM is updated from the Pre-Delta-X DEM and extended to the full Delta-X study area. This DEM was developed from multiple data sources, including sonar data collected during Pre-Delta-X and Delta-X campaigns, bathymetric data from the Coastal Protection and Restoration Authority System-Wide Assessment and Monitoring System (CPRA SWAMP), and NOAA, and topography from the National Elevation Dataset and LiDAR from US Geological Survey (USGS). The provided data layers include the DEM, a binary water/land mask, data source flags, and eight layers with analysis weighting factors for each pixel. Elevation values are provided in meters with respect to the North American Vertical Datum of 1988 (NAVD88). The weighting factors indicate how each data source contributed to this multisource DEM. The data are provided in cloud-optimized GeoTIFF (CoG) format.

Digital elevation models (DEMs) of U.S. and other coasts that typically integrate ocean bathymetry and land topography. The DEMs 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. NOAA's National Centers for Environmental Information (NCEI) has built many of these models, and also distributes DEMs on behalf of other NOAA offices, as well national and international partners. Bathymetric, topographic, and shoreline data used in DEM development come from a variety of sources, including NOAA's National Ocean Service (NOS) and NCEI, the U.S. Geological Survey (USGS), the U.S. Army Corps of Engineers (USACE), and the Federal Emergency Management Agency (FEMA), as well as other federal, state, and local government agencies, academic institutions, and private companies. The DEMs are referenced to a variety of vertical tidal datums, typically mean high water (MHW) or North American Vertical Datum of 1988 (NAVD 88), and usually a horizontal datum of North American Datum of 1983 (NAD 83) or World Geodetic System 1984 (WGS84). DEM cell sizes range from high-resolution models (1/9 to 1/3 arc-second; ~3 to 10 meters) that support coastal inundation studies, to regional models (roughly 3 to 24 arc-seconds) that extend farther offshore, to global models (1 arc-minute; ~2 km).

This is a tiled collection of the 3D Elevation Program (3DEP) and is 1/3 arc-second (approximately 10 m) resolution. The 3DEP data holdings serve as the elevation layer of The National Map, and provide foundational elevation information for earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. The elevations in this DEM represent the topographic bare-earth surface. The seamless 1/3 arc-second DEM layers 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 continental United States, are referenced to the North American Vertical Datum of 1988 (NAVD88). The seamless 1/3 arc-second DEM layer provides coverage of the conterminous United States, Hawaii, Puerto Rico, other territorial islands, and in limited areas of Alaska. The seamless 1/3arc-second DEM is available as pre-staged current and historical products tiled in GeoTIFF format. The seamless 1/3 arc-second DEM layer is updated continually as new data become available in the current folder. Previously created 1 degree blocks are retained in the historical folder with an appended date suffix (YYYMMDD) when they were produced. Other 3DEP products are nationally seamless DEMs in resolutions of 1, and 2 arc seconds. These seamless DEMs were referred to as the National Elevation Dataset (NED) from about 2000 through 2015 at which time they became the seamless DEM layers under the 3DEP program and the NED name and system were retired. Other 3DEP products include one-meter DEMs produced exclusively from high resolution light detection and ranging (lidar) source data and five-meter DEMs in Alaska as well as various source datasets including the lidar point cloud and interferometric synthetic aperture radar (Ifsar) digital surface models and intensity images. All 3DEP products are public domain.

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.

1:250000 scale Digital Elevation Model of Arizona. Digital Elevation Model (DEM) is the terminology adopted by the USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of a regular array of elevations cast on a designated coordinate projection system. The DEM data are stored as a series of profiles in which the spacing of the elevations along and between each profile is in regular whole number intervals. The normal orientation of data is by columns and rows. Each column contains a series of elevations ordered from south to north with the order of the columns from west to east. The DEM is formatted as one ASCII header record (A-record), followed by a series of profile records (B-records) each of which include a short B-record header followed by a series of ASCII integer elevations per each profile. The last physical record of the DEM is an accuracy record (C-record). A 30-minute DEM (2- by 2-arc second data spacing) consists of four 15-by 15-minute DEM blocks. Two 30-minute DEM's provide the same coverage as a standard USGS 30- by 60-minute quadrangle. Saleable units are 30- by 30-minute blocks, that is, four 15- by 15-minute DEM's representing one half of a 1:100,000-scale map.

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=179.99583333333334 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=179.99583333333334 geospatial_lon_min=-179.99583333333334 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=-179.99583333333334

This resource contains Lidar-DEM collection status shapefiles from the Texas Natural Resources Information System (TNRIS) [http://tnris.org]. November 2023 updates: this year, TNRIS changed its name to Texas Geographic Information Office (TxGIO). The domain name hasn't changed yet, but the data hub is continually evolving. See [1], [2] for current downloadable data.

For purposes of Hurricane Harvey studies, the 1-m DEM for Harris County (2008) has also been uploaded here as a set of 4 zipfiles containing the DEM in tiff files. See [1] for a link to the current elevation status map and downloadable DEMs.
Project name: H-GAC 2008 1m Datasets: 1m Point Cloud, 1M Hydro-Enforced DEM, 3D Breaklines, 1ft and 5ft Contours Points per sq meter: 1 Total area: 3678.56 sq miles Source: Houston-Galveston Area Council (H-GAC) Acquired by: Merrick, QA/QC: Merrick Catalog: houston-galveston-area-council-h-gac-2008-lidar

References: [1] TNRIS/TxGIO StratMap elevation data [https://tnris.org/stratmap/elevation-lidar/] [2] TNRIS/TxGIO DataHub [https://data.tnris.org/]

Tile Download Link MEDEM2 is a digital terrain elevation model of Maine with a 2 meter by 2 meter square grid or data spacing. Digital Elevation Model (DEM) is the terminology adopted by USGS to describe terrain elevation data sets in a digital raster form. The standard DEM consists of an array of elevations from ground positions at regularly spaced intervals, cast on a designated coordinate projection system. Elevation values are in meters. The data are a combination of DEMs from various lidar collections in Maine ranging from 2006 to 2013. The data overall are accurate to RSMEz 15cm.

Global 1-km resolution bathymetry from the 30 arc-second SRTM30+ gridded digital elevation model (DEM). Based on the Smith and Sandwell global 1 arc-minute grid between latitudes +/- 81 degrees. Higher resolution grids have been added from the LDEO Ridge Multibeam Synthesis Project, the JAMSTEC Data Site for Research Cruises, and the NOAA/NCEI Coastal Relief Model. Arctic bathymetry is from the International Bathymetric Chart of the Oceans (IBCAO). For a grayscale hillshade image layer of this dataset, see "world_srtm30plus_bathy1km_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 the Pacific Islands Ocean Observing System (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=179.99583333333334 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=179.99583333333334 geospatial_lon_min=-179.99583333333334 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 land surface data and converted to NetCDF format. id=srtm30plus_v11_bathy infoUrl=https://topex.ucsd.edu/WWW_html/srtm30_plus.html institution=Scripps Institution of Oceanography (SIO) instrument=In Situ/Laboratory Instruments > Profilers/Sounders > Acoustic Sounders > Sonar instrument_vocabulary=GCMD Instrument Keywords ISO_Topic_Categories=elevation, oceans keywords_vocabulary=GCMD Science Keywords locations=Geographic Region > Global Ocean locations_vocabulary=GCMD Location Keywords metadata_link=https://www.pacioos.hawaii.edu/metadata/srtm30plus_v11_bathy.html naming_authority=org.pacioos Northernmost_Northing=89.99583333333334 platform=In Situ Ocean-based Platforms > Ships, Models/Analyses > > DEM > Digital Elevation Model 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_bathy1km_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, Smith and Sandwell sourceUrl=https://pae-paha.pacioos.hawaii.edu/thredds/dodsC/srtm30plus_v11_bathy Southernmost_Northing=-89.99583333333334 standard_name_vocabulary=CF Standard Name Table v39 time_coverage_duration=P0D time_coverage_resolution=P0D Westernmost_Easting=-179.99583333333334

This is a tiled collection of the 3D Elevation Program (3DEP) and is 1/3 arc-second (approximately 10 m) resolution.The 3DEP data holdings serve as the elevation layer of The National Map, and provide foundational elevation information for earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. The elevations in this DEM represent the topographic bare-earth surface. The seamless 1/3 arc-second DEM layers 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 continental United States, are referenced to the North American Vertical Datum of 1988 (NAVD88). The seamless 1/3 arc-second DEM layer provides coverage of the conterminous United States, Hawaii, Puerto Rico, other territorial islands, and in limited areas of Alaska. The seamless 1/3 arc-second DEM is available as pre-staged products tiled in 1 degree blocks in Erdas .img, ESRI arc-grid, and grid float formats. The seamless 1/3 arc-second DEM layer is updated continually as new data become available. Other 3DEP products are nationally seamless DEMs in resolutions of 1, and 2 arc seconds. These seamless DEMs were referred to as the National Elevation Dataset (NED) from about 2000 through 2015 at which time they became the seamless DEM layers under the 3DEP program and the NED name and system were retired. Other 3DEP products include one-meter DEMs produced exclusively from high resolution light detection and ranging (lidar) source data and five-meter DEMs in Alaska as well as various source datasets including the lidar point cloud and interferometric synthetic aperture radar (Ifsar) digital surface models and intensity images. All 3DEP products are public domain.

This collection of the 3D Elevation Program (3DEP) is at 1/3 arc-second (approximately 10 m) resolution. The 3DEP data holdings serve as the elevation layer of The National Map, and provide foundational elevation information for earth science studies and mapping applications in the United States. Scientists and resource managers use 3DEP data for hydrologic modeling, resource monitoring, mapping and visualization, and many other applications. The elevations in this DEM represent the topographic bare-earth surface. The seamless 1/3 arc-second DEM layers 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 continental United States, are referenced to the North American Vertical Datum of 1988 (NAVD88). The vertical reference will vary in other areas. The seamless 1/3 arc-second DEM layer provides coverage of the conterminous United States, Hawaii, Puerto Rico, other territorial islands, and in limited areas of Alaska. These seamless DEMs were referred to as the National Elevation Dataset (NED) from about 2000 through 2015 at which time they became the seamless DEM layers under the 3DEP program and the NED name and system were retired. All 3DEP products are public domain.

This dataset contains the Digital Elevation Model (DEM) for North America from the Hydrologic Derivatives for Modeling and Analysis (HDMA) database. The DEM data were developed and distributed by processing units. There are 13 processing units for North America. The distribution files have the number of the processing unit appended to the end of the zip file name (e.g. na_dem_3_2.zip contains the DEM data for unit 3-2). The HDMA database provides comprehensive and consistent global coverage of raster and vector topographically derived layers, including raster layers of digital elevation model (DEM) data, flow direction, flow accumulation, slope, and compound topographic index (CTI); and vector layers of streams and catchment boundaries. The coverage of the data is global (-180º, 180º, -90º, 90º) with the underlying DEM being a hybrid of three datasets: HydroSHEDS (Hydrological data and maps based on SHuttle Elevation Derivatives at multiple Scales), Global Multi-resolution Terrain Elevation Data 2010 (GMTED2010) and the Shuttle Radar Topography Mission (SRTM). For most of the globe south of 60º North, the raster resolution of the data is 3-arc-seconds, corresponding to the resolution of the SRTM. For the areas North of 60º, the resolution is 7.5-arc-seconds (the smallest resolution of the GMTED2010 dataset) except for Greenland, where the resolution is 30-arc-seconds. The streams and catchments are attributed with Pfafstetter codes, based on a hierarchical numbering system, that carry important topological information.

The dataset is a 10 m-resolution DEM in grid format covering the whole Italian territory. The DEM is encoded as “ESRI ASCII Raster” obtained by interpolating the original DEM in Triangular Irregular Network (TIN) format. The TIN version benefited from the systematic application of the DEST algorithm. The projection is UTM, the World Geodetic System 1984 (WGS 84). To provide the dataset as a single seamless DEM, the sole zone 32 N was selected, although about half of Italy belongs to zone 33 N. The database is arranged in 193 square tiles having 50 km side. Data e Risorse Questo dataset non ha dati ambiente terremoti vulcani