This raster dataset contains LiDAR-derived elevation data flown from Fall 2015 to Spring 2016, with additional reflights through Fall 2016. This dataset encompasses all of the LARIAC4 project, comprised of approximately 4214 square miles.

The NOAA Office for Coastal Management (OCM) downloaded this digital elevation model (DEM) data from the USGS site: ftp://rockyftp.cr.usgs.gov/vdelivery/Data...

A digital elevation model (DEM) mosaic was produced for the Chandeleur Islands, Louisiana, from remotely sensed, geographically referenced elevation measurements collected by Leading Edge Geomatics (LEG) using a Leica Chiroptera II Bathymetric and Topographic Sensor. Dewberry reports that the nominal pulse spacing for this project was 1 point every 0.7 meters. Dewberry used proprietary procedures to classify the LAS according to project specifications: 0-Never Classified, 1-Unclassified, 2-Ground (includes model key point bit for points identified as Model Key Point), 7-Low Noise, 17-Bridges, 18-High Noise, 40-Bathymetric point or submerged topography (includes model key point bit for points identified as Model Key Point), 41-Water Surface, and 42-Derived water surface.

MD/PA Sandy Supplemental Lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00397 Woolpert Order No. 74333 CONTRACTOR: Woolpert, Inc. This task is for a high resolution data set of lidar covering approximately 1,845 square miles. The lidar data was acquired and processed under the requirements identified in this task order. Lidar data is a remotely sensed high resolution elevation data collected by an airborne platform. The lidar sensor uses a combination of laser range finding, GPS positioning, and inertial measurement technologies. The lidar systems collect data point clouds that are used to produce highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation. The task required the LiDAR data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. The final products include classified LAS, one (1) meter pixel raster DEMs of the bare-earth surface in ERDAS IMG Format, and 8-bit intensity images. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional deliverables include hydrologic breakline data, control data, tile index, lidar processing and survey reports in PDF format, FGDC metadata files for each data deliverable in .xml format, and LAS swath data. Ground conditions: Water at normal levels; no unusual inundation; no snow; leaf off. Coastal tiles 18SVH065720 and 8SVH095690 contain no lidar points as they exist completely in water. A DEM IMG was generated for these two tiles as the digitized hydro breakline assumed the data extent in the area. As such only 2568 LAS and Intensity files will be delivered along with 2570 DEM IMG's.This is a MD iMAP hosted service. Find more information at https://imap.maryland.gov.Image Service Link: https://mdgeodata.md.gov/lidar/rest/services/BaltimoreCity/MD_baltimorecity_dem_m/ImageServer

Purpose: To acquire detailed surface elevation data for use in conservation planning, design, research, floodplain mapping, dam safety assessments and elevation modeling, etc. Classified LAS files are used to show the manually reviewed bare earth surface. This allows the user to create intensity images, breaklines and raster DEMs. The purpose of these LiDAR data was to produce high accuracy 3D hydro-flattened digital elevation models (DEMs) with a 1-meter cell size. These raw LiDAR point cloud data were used to create classified LiDAR LAS files, intensity images, 3D breaklines, and hydro-flattened DEMs as necessary.Product: These are Digital Elevation Model (DEM) data for Northern Maine as part of the required deliverables for the Crown of Maine 2018 QL2 LiDAR project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1-meter hydro-flattened raster DEM.This lidar data set includes unclassified swath LAS 1.4 files, classified LAS 1.4 files, hydro and bridge breaklines, hydro-flattened digital elevation models (DEMs), and intensity imagery. Geographic Extent: 4 partial counties in Northern Maine, covering approximately 6,732 total square miles. Dataset Description: The Crown of Maine 2018 QL2 LiDAR project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.71 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LiDAR Specification, Version 1.2. The data were developed based on a horizontal projection/datum of NAD 1983 (2011), UTM Zone 19, meters and vertical datum of NAVD 1988 (GEOID 12B), meters. LiDAR data were delivered as processed Classified LAS 1.4 files formatted to 8,056 individual 1,500-meter x 1,500-meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500-meter x 1,500-meter schema. Continuous breaklines were produced in Esri file geodatabase format. Ground Conditions: LiDAR was collected in spring of 2018 and 2019, 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, Quantum Spatial, Inc. utilized a total of 150 ground control points that were used to calibrate the LiDAR to known ground locations established throughout the project area. An additional 256 independent accuracy checkpoints, 149 in Bare Earth and Urban landcovers (149 NVA points), 107 in Tall Weeds categories (107 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data.

This dataset is a LAS (industry-standard binary format for storing large point clouds) dataset containing light detection and ranging (LiDAR) data representing beach topography of Lake Superior at Minnesota Point, Duluth, Minnesota. Average point spacing of the LiDAR points in the dataset is 0.137 meters (m; 0.45 feet [ft]). The LAS dataset was used to create a 1-m (3.28084 ft) digital elevation model (DEM) of the approximately 4 kilometer (2.5 mile) surveyed reach of the beach. LiDAR data were collected August 10, 2019 using a boat-mounted Optech ILRIS scanner and methodology similar to that described by Huizinga and Wagner (2019).

Digital Elevation Model (DEM) dataset current as of 2009. LiDAR acquired and processed over the entire county to support the generation of 1"=100' scale orthophotos & 2' contours. The Lidar LAS data has been classified to bare-earth as well as first-return points..

The dataset is a digital elevation model (DEM), in GeoTiff format, of the bathymetry of Dierks Lake, Howard and Sevier Counties, Arkansas. The extent of the DEM represents the area encompassing the extent of the aerial Light Detection And Ranging (LiDAR) data used in the project. Horizontal and vertical units are expressed in meters. The DEM was derived from an LAS dataset (an industry-standard binary format for storing aerial LiDAR data) created from point datasets stored in “Dierks2018_gdb”. The point datasets include aerial LiDAR data from a survey conducted in 2016 by the National Resources Conservation Service (U.S. Geological Survey, 2017), point data from digitized historical topographic maps, and bathymetric data from a survey conducted in June 2018 by the Lower Mississippi-Gulf Water Science Center of the U.S. Geological Survey (USGS) using methodologies for single- and multi-beam sonar surveys similar to those described by Wilson and Richards (2006) and Richards and ...

MD/PA Sandy Supplemental Lidar Data Acquisition and Processing Production Task USGS Contract No. G10PC00057 Task Order No. G14PD00397 Woolpert Order No. 74333 CONTRACTOR: Woolpert, Inc. This task is for a high resolution data set of lidar covering approximately 1,845 square miles. The lidar data was acquired and processed under the requirements identified in this task order. Lidar data is a remotely sensed high resolution elevation data collected by an airborne platform. The lidar sensor uses a combination of laser range finding, GPS positioning, and inertial measurement technologies. The lidar systems collect data point clouds that are used to produce highly detailed Digital Elevation Models (DEMs) of the earth's terrain, man-made structures, and vegetation. The task required the LiDAR data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. The final products include classified LAS, one (1) meter pixel raster DEMs of the bare-earth surface in ERDAS IMG Format, and 8-bit intensity images. Each LAS file contains lidar point information, which has been calibrated, controlled, and classified. Additional deliverables include hydrologic breakline data, control data, tile index, lidar processing and survey reports in PDF format, FGDC metadata files for each data deliverable in .xml format, and LAS swath data. Ground conditions: Water at normal levels; no unusual inundation; no snow; leaf off. Coastal tiles 18SVH065720 and 8SVH095690 contain no lidar points as they exist completely in water. A DEM IMG was generated for these two tiles as the digitized hydro breakline assumed the data extent in the area. As such only 2568 LAS and Intensity files will be delivered along with 2570 DEM IMG's.This is a MD iMAP hosted service. Find more information at https://imap.maryland.gov.Image Service Link: https://mdgeodata.md.gov/lidar/rest/services/BaltimoreCity/MD_baltimorecity_dem_ft/ImageServer

This dataset is a LAS dataset containing light detection and ranging (lidar) data and multibeam sonar data representing the beach topography and near-shore bathymetry of Minnesota Point near the Duluth Entry of Lake Superior, Duluth, Minnesota. The LAS dataset used to create a digital elevation model (DEM) of the approximate 1.87 square kilometer surveyed area. Lidar data were collected using a boat mounted Velodyne VLP-16 unit. Multibeam sonar data were collected using a Norbit integrated wide band multibeam system compact (iWBMSc) sonar unit. Single-beam sonar data were collected using a Ceescope sonar unit. All elevation data were collected June 22-24, 2021. Methodology similar to Wagner, D.M., Lund, J.W., and Sanks, K.M., 2020 was used.

The Dauphin County, PA 2016 QL2 LiDAR project called for the planning, acquisition, processing and derivative products of LIDAR data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base LIDAR Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011) State Plane Pennsylvania South Zone, US survey feet; NAVD1988 (Geoid 12B), US survey feet. LiDAR data was delivered in RAW flight line swath format, processed to create Classified LAS 1.4 Files formatted to 711 individual 5,000-foot x 5,000-foot tiles. Tile names use the following naming schema: "YYYYXXXXPAd" where YYYY is the first 3 characters of the tile's upper left corner Y-coordinate, XXXX - the first 4 characters of the tile's upper left corner X-coordinate, PA = Pennsylvania, and d = 'N' for North or 'S' for South. Corresponding 2.5-foot gridded hydro-flattened bare earth raster tiled DEM files and intensity image files were created using the same 5,000-foot x 5,000-foot schema. Hydro-flattened breaklines were produced in Esri file geodatabase format. Continuous 2-foot contours were produced in Esri file geodatabase format. Ground Conditions: LiDAR collection began in Spring 2016, 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, Quantum Spatial established a total of 84 control points (24 calibration control points and 60 QC checkpoints). These were used to calibrate the LIDAR to known ground locations established throughout the project area.

Original Dataset Product: These are Digital Elevation Model (DEM) data for Northern Maine as part of the required deliverables for the Crown of Maine 2018 QL2 LiDAR project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1-meter hydro-flattened raster DEM. This lidar data set includes unclassified swath LAS 1.4 files, classified LAS 1.4 files, hydr...

Indiana's Statewide Lidar data is produced at 1.5-meter average post spacing for all 92 Indiana Counties covering more than 36,420 square miles. New Lidar data was captured except where previously captured Lidar data exists, or the participating County bought-up to a higher resolution of 1.0-meter average post spacing Lidar data. Existing Lidar data exists for: Porter, Steuben, Noble, De Kalb, Allen, Madison, Delaware, Hendricks, Marion, Hancock, Morgan, Johnson, Shelby, Monroe, and portions of Vermillion, Parke, Vigo, Clay, Sullivan, Knox, Gibson, and Posey. These existing Lidar datasets were seamlessly integrated into this new statewide dataset. From this seamless Lidar product a statewide 5-foot post spacing hydro-flattened DEM product was created and is also available. See the FGDC Metadata provided for more details.

This statewide project is divided into three geographic areas captured over a 3-year period (2011-2013):
Area 1 (2011) Indiana central counties: St. Joseph, Elkhart, Starke, Marshall, Kosciusko, Pulaski, Fulton, Cass, Miami, Wabash, Carroll, Howard, Clinton, Tipton, Boone, Hendricks, Marion, Morgan, Johnson, Monroe, Brown, Bartholomew, Lawrence, Jackson, Orange, Washington, Crawford, and Harrison.

Area 2 (2012) Indiana eastern counties: LaGrange, Steuben, Noble, DeKalb, Whitley, Allen, Huntington, Wells, Adams, Grant, Blackford, Jay, Hamilton, Madison, Delaware, Randolph, Hancock, Henry, Wayne, Shelby, Rush, Fayette, Union, Decatur, Franklin, Jennings, Ripley, Dearborn, Ohio, Scott, Jefferson, Switzerland, Clark, and Floyd.

Area 3 (2013) Indiana western counties: Lake, Porter, LaPorte, Newton, Jasper, Benton, White, Warren, Tippecanoe, Fountain, Montgomery, Vermillion, Parke, Putnam, Vigo, Clay, Owen, Sullivan, Greene, Knox, Daviess, Martin, Gibson, Pike, Dubois, Posey, Vanderburgh, Warrick, Spencer, and Perry.

Funders of OpenTopography Hosting of the Indiana Statewide Lidar and DEM data: USDA NRCS, Indiana, ISPLS Foundation, Indiana Geographic Information Office, Indiana Office of Technology, Indiana Geological Survey, Surdex Corporation, Vectren Energy Delivery, Indiana, Woolpert, Inc., and Individual IGIC Member Donations from Jim Stout, Jeff McCann, Cele Morris, Becky McKinley, Phil Worrall, and Andy Nicholson.

To explore a web map of topographic differencing for the entire state of Indiana click here

Index grid for locating and downloading original LAS and DEM datasets from the FL Peninsular and Hx Michael Supplemental LiDAR projects. Dashboard.

This layer contains the Point Cloud for LiDAR data in the Northland region, captured between 18 April 2024 - 28 June 2024.

The DEM is available as layer Northland LiDAR 1m DEM (2024).

The DSM is available as layer Northland LiDAR 1m DSM (2024).

The Index Tiles are available as layer Northland LiDAR Index Tiles (2024).

LiDAR was captured for Regional Software Holdings Ltd by Landpro Ltd from 18 April to 28 June 2024. The dataset was generated by Landpro and their subcontractors. Data management and distribution is by Toitū Te Whenua Land Information New Zealand.

Data comprises:

DEM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

DSM: tif or asc tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

Point cloud: las tiles in NZTM2000 projection, tiled into a 1:1,000 tile layout

Pulse density specification is at a minimum of 8 pulses/square metre.

Vertical Accuracy Specification is +/- 0.2m (95%) Horizontal Accuracy Specification is +/- 1.0m (95%)

Vertical datum is NZVD2016.

description: Product: These are Digital Elevation Model (DEM) data for Franklin, Oxford, Piscataquis, and Somerset Counties, Maine as part of the required deliverables for the 2016 Maine Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened raster DEM. Geographic Extent: Four partial counties in western Maine, covering approximately 5,034 total square miles Dataset Description: Maine 2016 QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011) UTM Zone 19, meters and vertical datum of NAVD1988 (Geoid 12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 6,115 individual 1,500 meter x 1,500 meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500 meter x 1,500 schema. Continuous breaklines were produced in Esri file geodatabase format. Continuous contours with an interval of 1 foot were created in Esri file geodatabase format. Ground Conditions: Lidar was collected in spring of 2016, 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, Quantum Spatial, Inc. utilized a total of 101 ground control points that were used to calibrate the lidar to known ground locations established throughout the Maine project area. An additional 205 independent accuracy checkpoints, 118 in Bare Earth and Urban landcovers (118 NVA points), 87 in Forested, Brushland/Trees, and Tall Weeds/Crops categories (87 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. In addition to the bare earth DEMs, the topobathy lidar point data are also available. These data are available for custom download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6264 Breaklines created from the lidar area also available for download in either gdb or gpkg format at: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/6264/breaklines. The DEM and breakline products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA, OCM or its partners.; abstract: Product: These are Digital Elevation Model (DEM) data for Franklin, Oxford, Piscataquis, and Somerset Counties, Maine as part of the required deliverables for the 2016 Maine Lidar project. Class 2 (ground) lidar points in conjunction with the hydro breaklines were used to create a 1 meter hydro-flattened raster DEM. Geographic Extent: Four partial counties in western Maine, covering approximately 5,034 total square miles Dataset Description: Maine 2016 QL2 Lidar project called for the planning, acquisition, processing, and derivative products of lidar data to be collected at a nominal pulse spacing (NPS) of 0.7 meters. Project specifications are based on the U.S. Geological Survey National Geospatial Program Base Lidar Specification, Version 1.2. The data was developed based on a horizontal projection/datum of NAD83 (2011) UTM Zone 19, meters and vertical datum of NAVD1988 (Geoid 12B), meters. Lidar data was delivered as flightline-extent unclassified LAS swaths, as processed Classified LAS 1.4 files formatted to 6,115 individual 1,500 meter x 1,500 meter tiles, as tiled intensity imagery, and as tiled bare earth DEMs; all tiled to the same 1,500 meter x 1,500 schema. Continuous breaklines were produced in Esri file geodatabase format. Continuous contours with an interval of 1 foot were created in Esri file geodatabase format. Ground Conditions: Lidar was collected in spring of 2016, 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, Quantum Spatial, Inc. utilized a total of 101 ground control points that were used to calibrate the lidar to known ground locations established throughout the Maine project area. An additional 205 independent accuracy checkpoints, 118 in Bare Earth and Urban landcovers (118 NVA points), 87 in Forested, Brushland/Trees, and Tall Weeds/Crops categories (87 VVA points), were used to assess the vertical accuracy of the data. These checkpoints were not used to calibrate or post process the data. In addition to the bare earth DEMs, the topobathy lidar point data are also available. These data are available for custom download here: https://coast.noaa.gov/dataviewer/#/lidar/search/where:ID=6264 Breaklines created from the lidar area also available for download in either gdb or gpkg format at: https://coast.noaa.gov/htdata/lidar2_z/geoid12b/data/6264/breaklines. The DEM and breakline products have not been reviewed by the NOAA Office for Coastal Management (OCM) and any conclusions drawn from the analysis of this information are not the responsibility of NOAA, OCM or its partners.

This dataset includes, LiDAR point cloud, DEM, hydro-conditioned DEM, and other calibration files. All geospatial data is available through the FWS Geospatial FileShare (EDW). FWS stores this dataset on the FWS Enterprise Data Warehouse for use in internal projects. There are no restrictions on this data, but it is very large and managed on an internal server. It is available to anyone on request.

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.

Original Product: Hydroflattened Digital Elevation Model (DEM) data covering the Central Eastern Massachusetts project area.

Original Dataset Geographic Extent: This dataset and derived products encompass an area covering approximately 5,246 Square Miles of Massachusetts.

Original Dataset Description: Lidar flight line swaths were processed to create 6,038 classified LAS 1.4 files delin...

Abstract

The dataset was derived by the Bioregional Assessment Programme from the 1 second SRTM Digital Elevation Model (DEM) dataset. The source dataset is identified in the Lineage field in this metadata statement. The processes undertaken to produce this derived dataset are described in the History field in this metadata statement.

A clipped version of the Australia wide 1 second -S DEM, version 1, which limits the size to the rectangular extent of the Galilee Basin Subregion, enhancing speed and efficiency for visualisation and processing.

The metadata for the Geoscience Australia 1 sec SRTM is below:

The 1 second DSM, DEM, DEM-S and DEM-H are national elevation data products derived from the Shuttle Radar Topography Mission (SRTM) data. The SRTM data is not suitable for routine application due to various artefacts and noise.

The data has been treated with several processes to produce more usable products:

\* A cleaned digital surface model (DSM)

\* regular grid representing ground surface topography as well as other features including vegetation and man-made structures

\* A bare-earth digital elevation model (DEM)

\* regular grid representing ground surface topography, and where possible, excluding other features such as vegetation and man-made structures.

\* A smoothed digital elevation model (DEM-S)

\* A smoothed DEM based on the bare-earth DEM that has been adaptively smoothed to reduce random noise typically associated with the SRTM data in low relief areas.

\* A hydrologically enforced digital elevation model (DEM-H)

\* A hydrologically enforced DEM is based on DEM-S that has had drainage lines imposed and been further smoothed using the ANUDEM interpolation software.

The last product, a hydrologically enforced DEM, is most similar to the DEMs commonly in use around Australia, such as the GEODATA 9 Second DEM and the 25 m resolution DEMs produced by State and Territory agencies from digitised topographic maps.

For any analysis where surface shape is important, one of the smoothed DEMs (DEM-S or DEM-H) should be used. DEM-S is preferred for shape and vertical accuracy and DEM-H for hydrological connectivity. The DSM is suitable if you want to see the vegetation as well as the land surface height. There are few cases where DEM is the best data source, unless access to a less processed product is necessary.

The 1 second DEM (in its various incarnations) has quite different characteristics to DEMs derived by interpolation from topographic data. Those DEMs are typically quite smooth and are based on fairly accurate but sparse source data, usually contours and spot heights supplemented by drainage lines. The SRTM data is derived from radar measurements that are dense (there is essentially a measurement at almost every grid cell) but noisy.

Version 1.0 of the DSM was released in early 2009 and version 1.0 of the DEM was released in late 2009. Version 1.0 of the DEM-S was released in July 2010 and version 1.0 of the hydrologically enforced DEM-H was released in October 2011. These products provide substantial improvements in the quality and consistency of the data relative to the original SRTM data, but are not free from artefacts. Improved products will be released over time.

The 3 second products were derived from the 1 second data and version 1.0 was released in August 2010. Future releases of these products will occur when the 1 second products have been improved. At this stage there is no 3 second DEM-H product, which requires re-interpolation with drainage enforcement at that resolution.

Purpose

To enhance the speed and efficiency for visualisation and processing of the smoothed 1 second DEM data within the Galilee Basin Subregion

Dataset History

The original, Australia wide, 1 second smoothed DEM was clipped to rectangular extents of the Galilee subregion using the Spatial Analyst 'Extract By Rectangle' tool in ESRI ArcCatalog v10.0 with the following parameters:

Input raster: source 1 second SRTM

Extent: Galilee Basin subregion polygon

Extraction Area: INSIDE

'no data' values are created outside the clip extent therefore the extent of the dataset may still reflect the national DEM extent in ArcCatalog. Check the tool details for more info.

The lineage of the source 1 second SRTM is below:

The following datasets were used to derive this version of the 1 second DEM products:

Source data

1. SRTM 1 second Version 2 data (Slater et al., 2006), supplied by Defence Imagery and Geospatial Organisation (DIGO) as 813 1 x 1 degree tiles. Data were produced by NASA from radar data collected by the Shuttle Radar Topography Mission in February 2000.

2. GEODATA 9 second DEM Version 3 (Geoscience Australia, 2008) used to fill voids.

3. SRTM Water Body Data (SWBD) shapefile accompanying the SRTM data (Slater et al., 2006). This defines the coastline and larger inland waterbodies for the DEM and DSM.

4. Vegetation masks and water masks applied to the DEM to remove vegetation.

Full metadata, methodologies and lineage descriptions can be found in the PDF userguide within this dataset.

Dataset Citation

Bioregional Assessment Programme (2014) Smoothed Digital Elevation Model (DEM) - 1 arc second resolution - Clipped to Galilee Subregion extent. Bioregional Assessment Derived Dataset. Viewed 10 December 2018, http://data.bioregionalassessments.gov.au/dataset/0fe257aa-8845-4183-9d05-5b48edd98f34.

Dataset Ancestors

• Derived From Geoscience Australia, 1 second SRTM Digital Elevation Model (DEM)

Abstract

The dataset was derived by the Bioregional Assessment Programme from the Geoscience Australia, 1 second SRTM Digital Elevation Model (DEM) dataset. The source dataset is identified in the Lineage field in this metadata statement. The processes undertaken to produce this derived dataset are described in the History field in this metadata statement.

This dataset provides a userguide and setup information relating to accessing the Geoscience Australia, 1 second SRTM Digital Elevation Model (DEM), for visualisation and analysis using ESRI ArcMap and ArcCatalog.

The 1 second DSM, DEM, DEM-S and DEM-H are national elevation data products derived from the Shuttle Radar Topography Mission (SRTM) data. The SRTM data is not suitable for routine application due to various artifacts and noise.

The data has been treated with several processes to produce more usable products:

* A cleaned digital surface model (DSM)

o regular grid representing ground surface topography as well as other features including vegetation and man-made structures

* A bare-earth digital elevation model (DEM)

o regular grid representing ground surface topography, and where possible, excluding other features such as vegetation and man-made structures.

* A smoothed digital elevation model (DEM-S)

o A smoothed DEM based on the bare-earth DEM that has been adaptively smoothed to reduce random noise typically associated with the SRTM data in low relief areas.

* A hydrologically enforced digital elevation model (DEM-H)

o A hydrologically enforced DEM is based on DEM-S that has had drainage lines imposed and been further smoothed using the ANUDEM interpolation software.

The last product, a hydrologically enforced DEM, is most similar to the DEMs commonly in use around Australia, such as the GEODATA 9 Second DEM and the 25 m resolution DEMs produced by State and Territory agencies from digitised topographic maps.

For any analysis where surface shape is important, one of the smoothed DEMs (DEM-S or DEM-H) should be used. DEM-S is preferred for shape and vertical accuracy and DEM-H for hydrological connectivity. The DSM is suitable if you want to see the vegetation as well as the land surface height. There are few cases where DEM is the best data source, unless access to a less processed product is necessary.

The 1 second DEM (in its various incarnations) has quite different characteristics to DEMs derived by interpolation from topographic data. Those DEMs are typically quite smooth and are based on fairly accurate but sparse source data, usually contours and spot heights supplemented by drainage lines. The SRTM data is derived from radar measurements that are dense (there is essentially a measurement at almost every grid cell) but noisy.

Version 1.0 of the DSM was released in early 2009 and version 1.0 of the DEM was released in late 2009. Version 1.0 of the DEM-S was released in July 2010 and version 1.0 of the hydrologically enforced DEM-H was released in October 2011. These products provide substantial improvements in the quality and consistency of the data relative to the original SRTM data, but are not free from artefacts. Improved products will be released over time.

The 3 second products were derived from the 1 second data and version 1.0 was released in August 2010. Future releases of these products will occur when the 1 second products have been improved. At this stage there is no 3 second DEM-H product, which requires re-interpolation with drainage enforcement at that resolution.

Dataset History

See readme file: readme file for gloucester basin 1sec srtm.xyz

This is ascii file created by CSIRO 3 september 2013 using Geosoft Oasis Montaj software

file is 1 second shuttle radar data (28.6 x 28.6 m) which has had buildings and vegetation removed

(processing by CSIRO and GA) DEM-S product

file format is gda94 easting, gda94 northing, height above sea level

mga zone 56 coordinates, all data in metres

origin (bottom left) is 379007E, 6400022N

1260 pts in east direction

2798 pts in north direction

Dataset Citation

Bioregional Assessment Programme (XXXX) GLO DEM 1sec SRTM MGA56. Bioregional Assessment Derived Dataset. Viewed 18 July 2018, http://data.bioregionalassessments.gov.au/dataset/ca38ed31-e15d-4bb5-a7ef-0aeba3dad3f4.

Dataset Ancestors

• Derived From Geoscience Australia, 1 second SRTM Digital Elevation Model (DEM)