Hydro-Flattened Bare Earth DTM - 1m resolution. The dataset contains the 1m Digital Surface Model for the District of Columbia. Some areas have limited data. The lidar dataset redaction was conducted under the guidance of the United States Secret Service. Except for classified ground points and classified water points, all lidar data returns and collected data were removed from the dataset within the United States Secret Service 1m redaction boundary generated for the 2017 orthophoto flight. This dataset provided as an ArcGIS Image service. Please note, the download feature for this image service in Open Data DC provides a compressed PNG, JPEG or TIFF. The compressed MrSID mosaic raster dataset is available under additional options when viewing downloads. Requests for the individual GeoTIFF set of images should be sent to open.data@dc.gov.

The hydro-flattened bare earth DEM was generated using the 2018 DC lidar bare earth points and 3D hydro breaklines to a resolution of 1 m. The bare earth points that fell within 1NPS along the hydro breaklines were excluded from the DEM generation process and put into class 20 – ignored ground. This is analogous to the removal of mass points for the same reason in a traditional photogrammetrically compiled DTM. This process was done in batch using proprietary software. The technicians then used proprietary software for the production of the lidar-derived hydro-flattened bare earth DEM surface in initial grid format at 1 m GSD. Water bodies (inland ponds and lakes), inland streams and rivers, and island holes were hydro-flattened within the DEM. Once the initial, hydro-flattened bare earth DEM was generated, the tiles were checked to ensure that the grid spacing met specifications. The surface was also checked to ensure proper hydro-flattening.This dataset provided as an ArcGIS Image service. Please note, the download feature for this image service in Open Data DC provides a compressed PNG, JPEG or TIFF. The compressed GeoTIFF raster dataset is available under additional options when viewing downloads.

Light Detection and Ranging (LiDAR) data is remotely sensed high-resolution elevation data collected by an airborne collection platform. This LiDAR dataset is a survey of Coastal California. The project area consists of approximately 2616 square miles. The project design of the LiDAR data acquisition was developed to support a nominal post spacing of 1 meter. Fugro EarthData, Inc. acquired 1546 flight lines in 108 lifts between October 2009 and August 2011. LiDAR data collection was performed with two Piper Navajo twin engine aircrafts, utilizing a Leica ALS60 MPiA sensor; collecting multiple return x, y, and z as well as intensity data. The bare-earth lidar data was used to create hydro-flattened DEMs (Digital Elevation Models) available for download from the NOAA OCM Digital Coast.

Product: 1-meter bare-earth raster digital elevation model (DEM) data tiles in GeoTIFF format. Geographic Extent: Approximately 4,028 square miles encompassing the Big Island of Hawaii. Dataset Description: The HI Hawaii Island Lidar NOAA 2017 B17 lidar project called for the planning, acquisition, processing, and production of derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.35 meters. Project specifications were based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification 2020 Revision A. The data was developed based on a horizontal datum/projection of NAD83 (PA11) UTM Zone 5N Meters (EPSG 6635) and a vertical datum of NAVD88 (GEOID1B) Meters. DEM data was delivered as Geo files formatted to 8,629 individual 1,000-meter x 1,000-meter tiles. Ground Conditions: Lidar was collected from January 30, 2018 through January 6, 2020 by Leica Geosystems, Inc. while no snow was on the ground and rivers were at or below normal levels. In order to post process the lidar data to meet task order specifications and meet ASPRS vertical accuracy guidelines, Woolpert established 70 ground control points that were used to calibrate the lidar to known ground locations established throughout the project area. An additional 0 independent accuracy checkpoints (0 NVA points and 0 VVA points), were collected and used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. Areas near cliffs with dense vegetation may have poor interpolations over voids. Please see the data use constraints section.

A bare earth digital elevation model (DEM) represents the earth's surface with all vegetation and human-made structures removed. The bare earth DEMs were derived from LiDAR data using triangulated irregular network (TIN) processing of the ground point returns. Hydro-flattened Bare Earth DEMs represent water bodies in a cartographically and aesthetically pleasing manner, and are not intended to accurately map water surface elevations. In a Hydro-flattened DEM, water surfaces are flat and level for lakes with a greater area than two acres, and gradated for rivers or other long impoundments (e.g., reservoirs) that are wider than 100 feet, and tidal areas. Any existing island larger than one acre was be delineated. Water surface edge elevations were at or below the immediately surrounding terrain. Each image corresponds to a 37,800-square-foot tile. Each pixel is 3 feet and represents an average elevation for that area. The specified coordinate system for this dataset is California State Plane Zone II (FIPS 0402), NAD83 (2011), with units in US Survey Feet for horizontal, and vertical units are NAVD88 (12A) US Survey Feet. The dataset encompasses a portion of Sonoma County. WSI collected the LiDAR and created this data set for the Sonoma County Vegetation Mapping and LiDAR Consortium.

A bare earth digital elevation model (DEM) represents the earth's surface with all vegetation and human-made structures removed. The bare earth DEMs were derived from LiDAR data using triangulated irregular network (TIN) processing of the ground point returns. Hydro-flattened Bare Earth DEMs represent water bodies in a cartographically and aesthetically pleasing manner, and are not intended to accurately map water surface elevations. In a Hydro-flattened DEM, water surfaces are flat and level for lakes with a greater area than two acres, and gradated for rivers or other long impoundments (e.g., reservoirs) that are wider than 100 feet, and tidal areas. Any existing island larger than one acre was be delineated. Water surface edge elevations were at or below the immediately surrounding terrain. Each image corresponds to a 37,800-square-foot tile. Each pixel is 3 feet and represents an average elevation for that area. The specified coordinate system for this dataset is California State Plane Zone II (FIPS 0402), NAD83 (2011), with units in US Survey Feet for horizontal, and vertical units are NAVD88 (12A) US Survey Feet. The dataset encompasses all of Sonoma County and parts of Mendocino County. WSI collected the LiDAR and created this data set for the Sonoma County Vegetation Mapping and LiDAR Program.Data hosted by Sonoma County Information Systems Department (ISD).

(Link to Metadata) This metadata applies to the following collection area(s): Eastern VT 2014 0.7m and Digital Elevation Model (DEM) dataset of the following "hydro-treatment": DEMHF. This metadata complies with the VT Geodata Portal format and applies to thematic layers with the same resolution (RESCLASS), e.g., 0p7m, 1m etc., and may include multiple data "collection" efforts. For the original vendor metadata containing specific details on each collections "point cloud" such as flight dates, nominal pulse spacing and RMSEz etc., see the "All Available LiDAR" Product page: (http://vcgi.vermont.gov/warehouse/products/ALL-LDR_MIX_LIDAR_STATE_ALL). Available DEMs vary by collection and can include the following 'hydro treatment' DEMs: 1) ElevationDEM: ("pure" Bare Earth) - no treatments, i.e., a bare ground surface without objects like vegetation and buildings; 2) ElevationDEMHF: (DEM Hydro-Flattened)- Cartographic/Aesthetic enhancement of (topographic) surface by removal of LiDAR artifacts in water. Constant elevation for waterbodies and suitable for contouring. Building voids remain due to cost; and 3) ElevationDEMHE*: (DEM Hydro-Enforced): A (hydrologic) surface with drain connectivity used by engineers in Hydraulic and Hydrologic (H&H) modeling. NOT for traditional mapping (contours, etc.). Like DEM_HF but added Single Line Breaklines: Pipelines, Culverts, Underground Streams, etc. For an overview of the "Vermont LiDAR Initiative" please see "http://vcgi.vermont.gov/lidar".

Hydro-Flattened Bare Earth DTM - 1m resolution. The dataset contains the 1m Digital Surface Model for the District of ColumbiaSome areas have limited data. The lidar dataset redaction was conducted under the guidance of the United States Secret Service. Except for classified ground points and classified water points, all lidar data returns and collected data were removed from the dataset within the United States Secret Service 1m redaction boundary generated for the 2017 orthophoto flight

Hydro-Flattened Bare Earth DTM. The dataset was created using the lidar bare earth points and 3D hydro breaklines to a resolution of 1 m (April 2018).Voids exist in the data due to data redaction conducted under the guidance of the United States Secret Service. All lidar data returns and collected data were removed from the dataset based on the redaction footprint shapefile generated in 2017.

(Link to Metadata) This metadata applies to the following collection area: Rutland/GI Counties 2013 0.7m and Digital Elevation Model (DEM) datasets of various "hydro-treatments": *DEM, *DEMHF & DEMHE. This metadata complies with the VT Geodata Portal format and applies to thematic layers with the same resolution (RESCLASS), e.g., 0p7m, 1m etc., and may include multiple data "collection" efforts. For the original vendor metadata containing specific details on each collections "point cloud" such as flight dates, nominal pulse spacing and RMSEz etc., see the "All Available LiDAR" Product page: (http://vcgi.vermont.gov/warehouse/products/ALL-LDR_MIX_LIDAR_STATE_ALL). Available DEMs vary by collection and can include the following 'hydro treatment' DEMs: 1) ElevationDEM: ("pure" Bare Earth) - no treatments, i.e., a bare ground surface without objects like vegetation and buildings; 2) ElevationDEMHF: (DEM Hydro-Flattened)- Cartographic/Aesthetic enhancement of (topographic) surface by removal of LiDAR artifacts in water. Constant elevation for waterbodies and suitable for contouring. Building voids remain due to cost; and 3) ElevationDEMHE*: (DEM Hydro-Enforced): A (hydrologic) surface with drain connectivity used by engineers in Hydraulic and Hydrologic (H&H) modeling. NOT for traditional mapping (contours, etc.). Like DEM_HF but added Single Line Breaklines: Pipelines, Culverts, Underground Streams, etc. For an overview of the "Vermont LiDAR Initiative" please see "http://vcgi.vermont.gov/lidar".

(Link to Metadata) This metadata applies to the following collection area(s): Windham County 2015 0.7m and Digital Elevation Model (DEM) dataset of the following "hydro-treatment": DEMHF. This metadata complies with the VT Geodata Portal format and applies to thematic layers with the same resolution (RESCLASS), e.g., 0p7m, 1m etc., and may include multiple data "collection" efforts. For the original vendor metadata containing specific details on each collections "point cloud" such as flight dates, nominal pulse spacing and RMSEz etc., see the "All Available LiDAR" Product page: (http://vcgi.vermont.gov/warehouse/products/ALL-LDR_MIX_LIDAR_STATE_ALL). Available DEMs vary by collection and can include the following 'hydro treatment' DEMs: 1) ElevationDEM: ("pure" Bare Earth) - no treatments, i.e., a bare ground surface without objects like vegetation and buildings; 2) ElevationDEMHF: (DEM Hydro-Flattened)- Cartographic/Aesthetic enhancement of (topographic) surface by removal of LiDAR artifacts in water. Constant elevation for waterbodies and suitable for contouring. Building voids remain due to cost; and 3) ElevationDEMHE*: (DEM Hydro-Enforced): A (hydrologic) surface with drain connectivity used by engineers in Hydraulic and Hydrologic (H&H) modeling. NOT for traditional mapping (contours, etc.). Like DEM_HF but added Single Line Breaklines: Pipelines, Culverts, Underground Streams, etc. For an overview of the "Vermont LiDAR Initiative" please see "http://vcgi.vermont.gov/lidar".

Product: These are Digital Elevation Model (DEM) data for CT Statewide GIS Services as part of the required deliverables for the CT Statewide GIS Services Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 2 foot hydro-flattened Raster DEM. Geographic Extent: CT Statewide covering approximately 5,241 square miles. Dataset Description:...

(Link to Metadata) This metadata applies to the following collection area(s): Middle CT River subbasin 2016 0.7m and Digital Elevation Model (DEM) dataset of the following "hydro-treatment": DEMHF. This metadata complies with the VT Geodata Portal format and applies to thematic layers with the same resolution (RESCLASS), e.g., 0p7m, 1m etc., and may include multiple data "collection" efforts. For the original vendor metadata containing specific details on each collections "point cloud" such as flight dates, nominal pulse spacing and RMSEz etc., see the "All Available LiDAR" Product page: (http://vcgi.vermont.gov/warehouse/products/ALL-LDR_MIX_LIDAR_STATE_ALL). Available DEMs vary by collection and can include the following 'hydro treatment' DEMs: 1) ElevationDEM: ("pure" Bare Earth) - no treatments, i.e., a bare ground surface without objects like vegetation and buildings; 2) ElevationDEMHF: (DEM Hydro-Flattened)- Cartographic/Aesthetic enhancement of (topographic) surface by removal of LiDAR artifacts in water. Constant elevation for waterbodies and suitable for contouring. Building voids remain due to cost; and 3) ElevationDEMHE*: (DEM Hydro-Enforced): A (hydrologic) surface with drain connectivity used by engineers in Hydraulic and Hydrologic (H&H) modeling. NOT for traditional mapping (contours, etc.). Like DEM_HF but added Single Line Breaklines: Pipelines, Culverts, Underground Streams, etc. For an overview of the "Vermont LiDAR Initiative" please see "http://vcgi.vermont.gov/lidar".

This bare earth hydro flattened digital elevation model (DEM) represents the earth's surface with all vegetation and human-made structures removed and hydro flattening performed within the OLC Santiam defined project area. Bare Earth Hydro Flattened DEMs were derived from LiDAR data using TIN processing of the ground point returns. The DEM grid cell size is 1 meter. The dataset encompasses 110,...

NYC 1foot Digital Elevation Model: A bare-earth, hydro-flattened, digital-elevation surface model derived from 2010 Light Detection and Ranging (LiDAR) data. Surface models are raster representations derived by interpolating the LiDAR point data to produce a seamless gridded elevation data set. A Digital Elevation Model (DEM) is a surface model generated from the LiDAR returns that correspond to the ground with all buildings, trees and other above ground features removed. The cell values represent the elevation of the ground relative to sea level. The DEM was generated by interpolating the LiDAR ground points to create a 1 foot resolution seamless surface. Cell values correspond to the ground elevation value (feet) above sea level. A proprietary approach to surface model generation was developed that reduced spurious elevation values in areas where there were no LiDAR returns, primarily beneath buildings and over water. This was combined with a detailed manual QA/QC process, with emphasis on accurate representation of docks and bare-earth within 2000ft of the water bodies surrounding each of the five boroughs. Please see the following link for additional documentation- https://github.com/CityOfNewYork/nyc-geo-metadata/blob/master/Metadata/Metadata_DigitalElevationModel.md

This project will support the USDA Natural Resources Conservation Service (NRCS) high resolution elevation enterprise program, state and local agencies in Rhode Island, and the United States Geological Survey (USGS) 3DEP mission.A hillshade rendition of the hydro-flattened, continuous bare earth surface (excluding trees, buildings, manmade structures), raster-formatted, high resolution (1ft) Digital Elevation Model (DEM).This dataset was developed from the USDA Natural Resources Conservation Service (NRCS)-United States Geological Survey (USGS)-commissioned spring leaf-off 2022 statewide, high density, topographic data quality level 1 (QL1) lidar elevation source.The source lidar elevation point cloud and geospatial data products were collected, processed, validated and documented according to the requirements set forth in the USGS National Geospatial Program’s (NGP) Lidar Base Specification (LBS) 2022 rev. A, providing consistency, credibility and reliability through a set of standards developed through developed through the USGS 3D Elevation Program(3DEP).Access Raw Data Files Here

Snow and ice-covered Mount Baker in northern Washington, is the highest peak in the North Cascades (3,286 meters or 10,781 feet) and the northernmost volcano in the conterminous United States. It is the only U.S. volcano in the Cascade Range that has been affected by both alpine and continental glaciation. The stratovolcano is composed mainly of andesite lava flows and breccias formed prior to the most recent major glaciation (Fraser Glaciation), which occurred between about 25,000 and 10,000 years ago. The most recent major eruption at Mount Baker (6,700 years ago) was accompanied by a major flank-collapse event that caused lahars to rush down the Nooksack River and then eastward into Baker Lake. In 1975-76, Sherman Crater immediately south of the summit, exhibited signs of renewed volcanic activity as a result of magma intruding into the volcano but not erupting. The DEM (digital elevation model) of Mount Baker covers approximately 201 square miles and is the product of high-precision airborne lidar (Light Detection and Ranging) surveys performed between 08/26/15 and 09/27/15 by Quantum Spatial under contract with the USGS. The DEM, represents the ground surface beneath forest cover. This release includes two raster datasets in .tif format, (1) a DEM dataset (mt_baker_dem.zip, 1.40 GB), and (2) a hillshade raster (mt_baker_hillshade.zip, 573 MB).

(Link to Metadata) This metadata applies to the following collection area(s): Addison County 2012 1.6m and Digital Elevation Model (DEM) datasets of various "hydro-treatments": *DEM, *DEMHF & DEMHE. This metadata complies with the VT Geodata Portal format and applies to thematic layers with the same resolution (RESCLASS), e.g., 0p7m, 1m etc., and may include multiple data "collection" efforts. For the original vendor metadata containing specific details on each collections "point cloud" such as flight dates, nominal pulse spacing and RMSEz etc., see the "All Available LiDAR" Product page: (http://vcgi.vermont.gov/warehouse/products/ALL-LDR_MIX_LIDAR_STATE_ALL). Available DEMs vary by collection and can include the following 'hydro treatment' DEMs: 1) ElevationDEM: ("pure" Bare Earth) - no treatments, i.e., a bare ground surface without objects like vegetation and buildings; 2) ElevationDEMHF: (DEM Hydro-Flattened)- Cartographic/Aesthetic enhancement of (topographic) surface by removal of LiDAR artifacts in water. Constant elevation for waterbodies and suitable for contouring. Building voids remain due to cost; and 3) ElevationDEMHE*: (DEM Hydro-Enforced): A (hydrologic) surface with drain connectivity used by engineers in Hydraulic and Hydrologic (H&H) modeling. NOT for traditional mapping (contours, etc.). Like DEM_HF but added Single Line Breaklines: Pipelines, Culverts, Underground Streams, etc. For an overview of the "Vermont LiDAR Initiative" please see "http://vcgi.vermont.gov/lidar".

This dataset is a bare earth (vegetation removed) digital elevation model (DEM) of Pine County, Minnesota. The download file includes 1-meter and 3-meter DEMs, a 3-meter hillshade, 2-foot contours, slope and validation points. The data is FEMA-compliant.

Lidar data for Pine County, Minnesota, was collected under contract by the Natural Resources Conservation Service. Thus, the data format is not entirely consistent with some of the other lidar data collected by the State of Minnesota. Specifically, the Pine County collect did not require classification of anything other than Bare Earth in the lidar LAS files, so there is no information on buildings, vegetation, or model key points. There are also no edge-of-water breaklines so the DEMs have not been hydro flattened.

This metadata record was created at the Minnesota Geospatial Information Office by combining information from Sanborn Mapping, NRCS, and the Minnesota Department of Natural Resources.

A bare-earth, hydro-flattened, digital-elevation surface model derived from 2010 Light Detection and Ranging (LiDAR) data. Surface models are raster representations derived by interpolating the LiDAR point data to produce a seamless gridded elevation data set. A Digital Elevation Model (DEM) is a surface model generated from the LiDAR returns that correspond to the ground with all buildings, trees and other above ground features removed. The cell values represent the elevation of the ground relative to sea level. The DEM was generated by interpolating the LiDAR ground points to create a 1 foot resolution seamless surface. Cell values correspond to the ground elevation value (feet) above sea level. A proprietary approach to surface model generation was developed that reduced spurious elevation values in areas where there were no LiDAR returns, primarily beneath buildings and over water. This was combined with a detailed manual QA/QC process, with emphasis on accurate representation of docks and bare-earth within 2000ft of the water bodies surrounding each of the five boroughs.