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.

December 1995, June 2001

This data set contains the sea floor topographic contours, sun-illuminated topographic imagery, and backscatter intensity generated from a multibeam sonar survey of the Stellwagen Bank National Marine Sanctuary region off Boston, Massachusetts, an area of approximately 1100 square nautical miles. The Stellwagen Bank NMS Mapping Project is designed to provide detailed maps of the Stellwagen Bank region's environments and habitats and the first complete multibeam topographic and sea floor characterization maps of a significant region of the shallow EEZ. Data were collected on four cruises over a two year period from the fall of 1994 to the fall of 1996. The surveys were conducted aboard the Candian Hydrographic Service vessel Frederick G. Creed, a SWATH (Small Waterplane Twin Hull) ship that surveys at speeds of 16 knots. The multibeam data were collected utilizing a Simrad Subsea EM 1000 Multibeam Echo Sounder (95 kHz) that is permanently installed in the hull of the Creed.

MassGIS scanned the USGS topographic quadrangles to create a digital database that can provide images of the paper maps. These images can be used as a backdrop for plotting vector data and for interpretation and analysis. MassGIS scanned the 15-minute series (vintage 1982-1990) where these maps were available; the 7.5-minute maps (1967-1979) were used elsewhere. Note that the elevation labels for the contours on the maps may be in meters or feet, depending on the vintage of the original paper map that MassGIS scanned. Contour labels on maps from 1982 and later are in meters; labels on maps from 1967 through 1979 are in feet. See the

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 .

These data were created as part of the National Oceanic and Atmospheric Administration Office for Coastal Management's efforts to create an online mapping viewer called the Sea Level Rise and Coastal Flooding Impacts Viewer. It depicts potential sea level rise and its associated impacts on the nation's coastal areas. The purpose of the mapping viewer is to provide coastal managers and scientists with a preliminary look at sea level rise and coastal flooding impacts. The viewer is a screening-level tool that uses nationally consistent data sets and analyses. Data and maps provided can be used at several scales to help gauge trends and prioritize actions for different scenarios. The Sea Level Rise and Coastal Flooding Impacts Viewer may be accessed at: https://coast.noaa.gov/slr. This metadata record describes the Massachusetts digital elevation model (DEM), which is a part of a series of DEMs produced for the National Oceanic and Atmospheric Administration Office for Coastal Management's Sea Level Rise and Coastal Flooding Impacts Viewer described above. This DEM includes the best available lidar known to exist at the time of DEM creation that met project specifications. This DEM includes data for Barnstable, Bristol, Dukes, Essex, Middlesex, Nantucket, Plymouth, Suffolk, and Norfolk Counties. The DEM was produced from the following lidar data sets: 1. 2013 - 2014 USGS Hurricane Sandy Supplemental for NE (RI, MA, NH) 2. 2011 USGS ARRA Lidar for the Northeast: Massachusetts The DEM is referenced vertically to the North American Vertical Datum of 1988 (NAVD88, Geoid12B) with vertical units of meters and horizontally to the North American Datum of 1983 (NAD83). The resolution of the DEM is approximately 3 meters.

This is a seamless bare earth digital elevation model (DEM) created from lidar terrain elevation data for the Commonwealth of Massachusetts. It represents the elevation of the surface with vegetation and structures removed. The spatial resolution of the map is 1 meter. The elevation of each 1-meter square cell was linearly interpolated from classified lidar-derived point data.This version of the DEM stores the elevation values as integers. The native VALUE field represents the elevation above/below sea level in meters. MassGIS added a FEET field to the VAT (value attribute table) to store the elevation in feet as calculated by multiplying VALUE x 3.28084.Dates of lidar data used in this DEM range from 2010-2015. The overlapping lidar projects were adjusted to the same projection and datum and then mosaicked, with the most recent data replacing any older data. Several very small gaps between the project areas were patched with older lidar data where necessary or with models from recent aerial photo acquisitions. See https://www.mass.gov/doc/lidar-project-areas-original/download for an index map.This DEM is referenced to the WGS_1984_Web_Mercator_Auxiliary_Sphere spatial reference.See the MassGIS datalayer page to download the data as a file geodatabase raster dataset.View this service in the Massachusetts Elevation Finder.

Geospatial data about Worcester County, Massachusetts Contours. Export to CAD, GIS, PDF, CSV and access via API.

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 modeling 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).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 (MHW). 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.

The Massachusetts Statewide LiDAR from 2005 has been classified to show high elevations in Central and Western Massachusetts. The Digital Elevation Model has been classified as follows:Elevations below 1,700 feet are light blueElevations between 1,700 and 2,199 feet are light greenElevations between 2,200 and 3,000 feet are brownElevations greater than 3,000 feet are white. To view the full Massachusetts Forest Action Plan, click here. *For source data information, please see credits.

Bathymetry for Massachusetts Bay was derived from thirty-eight surveys containing 297,628 soundings. Two older, less accurate, overlapping surveys were omitted before tinning. The average separation between soundings was 57 meters. The thirty-eight surveys used dated from 1940 to 1970. The total range of soundings was 3.0 meters to -71.0 meters at mean low water. Mean high water values between 2.7 and 2.9 meters were assigned to the shoreline. Fifty-six points, predominantly from two surveys, were found that were not consistent with the surrounding data. These were removed prior to tinning. DEM grid values outside the shoreline (on land) were assigned null values (-32676). Massachusetts Bay has fifteen 7.5 minute DEMs and two one degree DEMs. The 1 degree DEMs were generated from the higher resolution 7.5 minute DEMs which covered the estuary. A Digital Elevation Model (DEM) 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 (typically in units of 1 centimeter) per each profile. The last physical record of the DEM is an accuracy record (C-record). The 7.5-minute DEM (30- by 30-m data spacing) is cast on the Universal Transverse Mercator (UTM) projection. It provides coverage in 7.5- by 7.5-minute blocks. Each product provides the same coverage as a standard USGS 7.5-minute quadrangle but the DEM contains over edge data. Coverage is available for many estuaries of the contiguous United States but is not complete.

The Elevation Contours service displays at large scales contour lines at 3-meter intervals created from Digital Terrain Model (DTM) data points collected during the production of the 1:5,000 Black and White Digital Orthophoto images. See https://www.mass.gov/info-details/massgis-data-elevation-contours-15000 for more details.At smaller scales the service displays contour lines at 30-foot intervals originally developed at a scale of 1:250,000 and distributed by the U.S. Geological Survey. Please see https://www.mass.gov/info-details/massgis-data-elevation-contours-1250000 for more details.For both datasets, the index contours are labeled in feet above sea level.

ESRI line feature class representing City of Somerville, Massachusetts 1-foot contour intervals.

The quadrangle template datalayer contains the boundaries of the 189 1:25,000 USGS 7.5-minute topographic map sheets that cover Massachusetts.See full metadata.

ASCII XYZ point cloud data were produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over Cape Cod National Seashore using the first-generation National Aeronautics and Space Administration (NASA) Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, 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 target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.

These digital elevation model (DEM) data consist of ground surface elevations derived from source lidar measurements collected in April and August 2022 in the vicinity of Petersham, MA during the SMAPVEX19-22 campaign. This location was chosen due to its forested land cover, as SMAPVEX19-22 aims to validate satellite derived soil moisture estimates in forested areas. The two acquisition periods occurred to characterize differences during "leaf-off” and "leaf-on" conditions.

Integrated terrain models covering 16,357 square kilometers of the Massachusetts coastal zone and offshore waters were built to provide a continuous elevation and bathymetry terrain model for ocean planning purposes. The area is divided into the following four geographical areas to reduce file size and facilitate publishing: Massachusetts Bay from the Massachusetts-New Hampshire border south to Provincetown and Scituate and east to Stellwagen Bank; Cape Cod Bay from Provincetown to Scituate and south to Hyannis; Buzzards Bay from the Cape Cod Canal southwest to the State border including the Elizabeth Islands and extending north to Fall River and Mount Hope Bay; and Nantucket and Vineyard Sounds, from Hyannis south to the border of the Massachusetts Coastal zone approximately 8 kilometers south of Nantucket. A Triangulated Irregular Network was created from public-domain bathymetric and LiDAR data using the ArcGIS terrain-model framework and then interpolated into a 32-bit GeoTiff of 10 meter resolution. The grids for each of the four geographical areas are referenced to the Universal Transverse Mercator, Zone 19, North American Datum of 1983 coordinate system, and the North American Vertical Datum of 1988. A polygon shapefile recording the source datasets accompanies each of the four grids.

description: A first-surface topography Digital Elevation Model (DEM) mosaic for the Cape Cod National Seashore was produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over Cape Cod National Seashore using the first-generation National Aeronautics and Space Administration (NASA) Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, 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 target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.; abstract: A first-surface topography Digital Elevation Model (DEM) mosaic for the Cape Cod National Seashore was produced from remotely sensed, geographically referenced elevation measurements acquired cooperatively by the U.S. Geological Survey (USGS) and the National Park Service (NPS). Elevation measurements were collected over Cape Cod National Seashore using the first-generation National Aeronautics and Space Administration (NASA) Experimental Advanced Airborne Research Lidar (EAARL), a pulsed laser ranging system mounted onboard an aircraft to measure ground elevation, vegetation canopy, 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 target area at approximately 60 meters per second at an elevation of approximately 300 meters, resulting in a laser swath of approximately 240 meters with an average point spacing of 2-3 meters. The EAARL, developed originally by NASA at Wallops Flight Facility in Virginia, measures ground elevation with a vertical resolution of 3 centimeters. A sampling rate of 3 kilohertz or higher results in an extremely dense spatial elevation dataset. Over 100 kilometers of coastline can be surveyed easily within a 3- to 4-hour mission. When resultant elevation maps for an area are analyzed, they provide a useful tool to make management decisions regarding land development.

Topographic map of Dedham, Massachusetts with contours and shaded relief. Shaded relief and contours were generated from LiDAR data collected on December 8th, 2013 and also April 7th, 2014.

The National Assessment of Coastal Change Hazards project derives beach morphology features from lidar elevation data for the purpose of understanding and predicting storm impacts to our nation's coastlines. This dataset defines beach slopes along the United States Northeast Atlantic Ocean for Massachusetts for data collected at various times between 2000 and 2013