The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering ~99% of England at 1m spatial resolution.The DTM (Digital Terrain Model) is produced from the last or only laser pulse returned to the sensor. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface. Produced by the Environment Agency in 2022, the DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme surveys, which have been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged. The 2022 LIDAR Composite contains surveys undertaken between 6th June 2000 and 2nd April 2022. Please refer to the metadata index catalgoues which show for any location which survey was used in the production of the LIDAR composite.DEFRA Data Services Platform Metadata URLDefra Network WMS server provided by the Environment Agency

Download In State Plane Projection Here The 2017 Digital Terrain Model (DTM) is a 2 foot pixel resolution raster in Erdas IMG format. This was created using the ground (class = 2) lidar points and incorporating the breaklines. The DTMs were developed using LiDAR data. LiDAR is an acronym for LIght Detection And Ranging. Light detection and ranging is the science of using a laser to measure distances to specific points. A specially equipped airplane with positioning tools and LiDAR technology was used to measure the distance to the surface of the earth to determine ground elevation. The classified points were developed using data collected in April to May 2017. The LiDAR points, specialized software, and technology provide the ability to create a high precision three-dimensional digital elevation and/or terrain models (DEM/DTM). The use of LiDAR significantly reduces the cost for developing this information. The DTMs are intended to correspond to the orthometric heights of the bare surface of the county (no buildings or vegetation cover). DTM data is used by county agencies to study drainage issues such as flooding and erosion; contour generation; slope and aspect; and hill shade images. This dataset was compiled to meet the American Society for Photogrammetry and Remote Sensing (ASPRS) Accuracy Standards for Large-Scale Maps, CLASS 1 map accuracy. The U.S. Army Corps of Engineers Engineering and Design Manual for Photogrammetric Production recommends that data intended for this usage scale be used for any of the following purposes: route location, preliminary alignment and design, preliminary project planning, hydraulic sections, rough earthwork estimates, or high-gradient terrain / low unit cost earthwork excavation estimates. The manual does not recommend that these data be used for final design, excavation and grading plans, earthwork computations for bid estimates or contract measurement and payment. This dataset does not take the place of an on-site survey for design, construction or regulatory purposes.

Unmanned Aerial System (UAS) flights were conducted over four stream catchments in Rio Blanco County, Colorado, during the summer of 2016. Two sties had active oil and gas operations within the basin whereas the other two sites did not. Structure from motion (SfM) was used to align raw images and create a dense point cloud, georectified orthoimage, and Digital Elevation Model (DEM) for each basin. A Digital Terrain Model (DTM), or bare earth model, for each basin was created by reclassifying the dense point cloud as either bare ground or other (vegetation, oil and gas infrastructure, etc.) and interpolating the land surface between bare ground points. Ideally, the DTM would always be equal or lower than the DEM; however, the interpolated surface can sometimes be higher than the DEM if bare ground points surround depressions with vegetation or in thick vegetation strands with an undulating surface. Therefore, a final surface model, created by merging the DTM with the DEM for all areas where the DTM was greater than the DEM, was produced for each basin. Lastly, a random forest classification approach was used to classify the orthoimagery on a pixel level into five vegetation/land cover classifications - bare ground, grass, litter, shrub/woody vegetation, and shadow.

The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering ~99% of England at 2m spatial resolution. The DTM (Digital Terrain Model) is produced from the last or only laser pulse returned to the sensor. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.

Produced by the Environment Agency in 2022, the DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme surveys, which have been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged.

The 2022 LIDAR Composite contains surveys undertaken between 6th June 2000 and 2nd April 2022. Please refer to the metadata index catalgoues which show for any location which survey was used in the production of the LIDAR composite.

The data is available to download as GeoTiff rasters in 5km tiles aligned to the OS National grid. The data is presented in metres, referenced to Ordinance Survey Newlyn and using the OSTN’15 transformation method. All individual LIDAR surveys going into the production of the composite had a vertical accuracy of +/-15cm RMSE.

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, aeroplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return. Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected between Jan. 2007 and Oct. 2017. An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of several DTM's mosaiced together.This data was collected by the Geological Survey Ireland, the Department of Culture, Heritage and the Gaeltacht, the Discovery Programme and the Heritage Council. All data formats are provided as GeoTIFF rasters but are at different resolutions. Data resolution varies depending on survey requirements from 0.125m to 1m.Both a DTM and DSM are raster data. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. The grid cell size varies depending on the organisation that collected it. GSI data has a grid cell size of 1 meter by 1 meter. This means that each cell (pixel) represents an area of 1 meter squared

The digital terrain model describes the terrain surface using a regular grid of points. The position and height of each grid point are known. The update will take place every 6 years from 2020/2021, but in new lot delimitations as available here.

Digital Terrain Model of the Gold Coast LGA, including bathymetry in certain areas. This dataset has been created from multiple data sources and surveys, details of which can be found in the associated metadata dataset - DTM Metadata

Disclaimer: The Digital Elevation Model (DEM) is a digital topographical representation of the City of Gold Coast. It was developed using Airborne Laser and bathymetric surveys of various accuracies and at different times. Thus the DEM accuracy can differ by at least 15cm to actual ground survey information which means that it will not be fit for all purposes.

PLEASE NOTE: This dataset has been retired. A new version of the data is available here: https://environment.data.gov.uk/dataset/ce8fe7e7-bed0-4889-8825-19b042e128d2

The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering >85% of England at 10m spatial resolution. This 10m model is a resampled version of the 2m DTM produced by the Environment Agency in 2019. The DTM is derived from a combination of our Time Stamped archive and National LIDAR Programme, which has been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged. A bilinear interpolation method was used to resampled from 2m to 10m resolution.

The 2019 LIDAR Composite contains surveys undertaken between 12th March 1998 and 1st September 2019. Please refer to the survey index files which shows, for any location, what Time Stamped survey or National LIDAR Programme block went into the production of the LIDAR composite for a specific location.

This resampled 10m dataset is available to download as a single GeoTiff Raster file from a sharefile link. Data is presented in metres, referenced to Ordinance Survey Newlyn, using the OSTN’15 transformation.

The DTM (Digital Terrain Model) is produced from the last return LIDAR signal. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface.

Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 500,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres. The Environment Agency’s open data LIDAR archives includes the point cloud data, and derived raster surface models of survey specific areas dating back to 1998 and composites of the best data available in any location.

This metadata record is for Approval for Access product AfA458. Attribution Statement: © Environment Agency copyright and/or database right 2020. All rights reserved.

Unmanned Aerial System (UAS) flights were conducted over four stream catchments in Rio Blanco County, Colorado, during the summer of 2016. Two sties had active oil and gas operations within the basin whereas the other two sites did not. Structure from motion (SfM) was used to align raw images and create a dense point cloud, georectified orthoimage, and Digital Elevation Model (DEM) for each basin. A Digital Terrain Model (DTM), or bare earth model, for each basin was created by reclassifying the dense point cloud as either bare ground or other (vegetation, oil and gas infrastructure, etc.) and interpolating the land surface between bare ground points. Ideally, the DTM would always be equal or lower than the DEM; however, the interpolated surface can sometimes be higher than the DEM if bare ground points surround depressions with vegetation or in thick vegetation strands with an undulating surface. Therefore, a final surface model, created by merging the DTM with the DEM for all areas where the DTM was greater than the DEM, was produced for each basin. Lastly, a random forest classification approach was used to classify the orthoimagery on a pixel level into five vegetation/land cover classifications - bare ground, grass, litter, shrub/woody vegetation, and shadow.

LiDAR (Light Detection and Ranging) is a remote sensing technology, i.e. the technology is not in direct contact with what is being measured. From satellite, airplane or helicopter, a LiDAR system sends a light pulse to the ground. This pulse hits the ground and returns back to a sensor on the system. The time is recorded to measure how long it takes for this light to return.Knowing this time measurement scientists are able to create topography maps.LiDAR data are collected as points (X,Y,Z (x & y coordinates) and z (height)). The data is then converted into gridded (GeoTIFF) data to create a Digital Terrain Model and Digital Surface Model of the earth. This LiDAR data was collected between Oct. 2006 and Jan. 2007. An ordnance datum (OD) is a vertical datum used as the basis for deriving heights on maps. This data is referenced to the Malin Head Vertical Datum which is the mean sea level of the tide gauge at Malin Head, County Donegal. It was adopted as the national datum in 1970 from readings taken between 1960 and 1969 and all heights on national grid maps are measured above this datum. Digital Terrain Models (DTM) are bare earth models (no trees or buildings) of the Earth’s surface.Digital Surface Models (DSM) are earth models in its current state. For example, a DSM includes elevations from buildings, tree canopy, electrical power lines and other features.Hillshading is a method which gives a 3D appearance to the terrain. It shows the shape of hills and mountains using shading (levels of grey) on a map, by the use of graded shadows that would be cast by high ground if light was shining from a chosen direction.This data shows the hillshade of the DTM.This data was collected by the Office of Public Works. All data formats are provided as GeoTIFF rasters. Raster data is another name for gridded data. Raster data stores information in pixels (grid cells). Each raster grid makes up a matrix of cells (or pixels) organised into rows and columns. OPW data has a grid cell size of 2 meter by 2 meter. This means that each cell (pixel) represents an area of 2 meter squared.

Digital Terrain Model of the Gold Coast LGA, including bathymetry in certain areas. This dataset has been created from multiple data sources and surveys, details of which can be found in the …Show full descriptionDigital Terrain Model of the Gold Coast LGA, including bathymetry in certain areas. This dataset has been created from multiple data sources and surveys, details of which can be found in the associated metadata dataset - DTM Metadata Disclaimer: The Digital Elevation Model (DEM) is a digital topographical representation of the City of Gold Coast. It was developed using Airborne Laser and bathymetric surveys of various accuracies and at different times. Thus the DEM accuracy can differ by at least 15cm to actual ground survey information which means that it will not be fit for all purposes.

The digital terrain model describes the terrain surface using a regular grid of points. The position and height of each grid point are known. The update will take place every 6 years from 2020/2021, but in new lot delimitations as available here.

The DTM is a homogeneous and regular point grid indicating the height of the ground level in order to model its surface. The DTM 1m is achieved by interpolating in Lambert 2008 source data in Lambert 72 and at a 1m-resolution from the Flemish and Brussels regions, and by adding Lambert 2008 data at 1m-resolution from the Walloon Region. The DTM 5m has an additional source, namely drawn structure lines and points adapted during systematic and continuous update by photogrammetric surveys. The DTM 20m is obtained by resampling of the DTM 1m.

PLEASE NOTE: This dataset has been retired. A new version of the data is available here: https://environment.data.gov.uk/dataset/09ea3b37-df3a-4e8b-ac69-fb0842227b04

The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering >93% of England at 2m spatial resolution.

Produced by the Environment Agency in 2020, this dataset is derived from a combination of our Time Stamped archive and National LIDAR Programme, which has been merged and re-sampled to give the best possible coverage. Where repeat surveys have been undertaken the newest, best resolution data is used. Where data was resampled a bilinear interpolation was used before being merged.

The 2020 LIDAR Composite contains surveys undertaken between 6th June 2000 and 1st September 2020. Please refer to the survey index files which shows, for any location, what Time Stamped survey or National LIDAR Programme block went into the production of the LIDAR composite for a specific location.

The DTM (Digital Terrain Model) is produced from the last return LIDAR signal. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface. Available to download as GeoTiff files in 5km grids, data is presented in metres, referenced to Ordinance Survey Newlyn, using the OSTN’15 transformation. All LIDAR data has a vertical accuracy of +/-15cm RMSE.

Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the distance between the aircraft and the ground. Up to 500,000 measurements per second are made of the ground, allowing highly detailed terrain models to be generated at spatial resolutions of between 25cm and 2 metres. The Environment Agency’s open data LIDAR archives includes the Point Cloud data, and derived raster surface models of survey specific areas dating back to 1998 and composites of the best data available in any location.

This metadata record is for Approval for Access product AfA458.

Attribution statement: (c) Environment Agency copyright and/or database right 2021. All rights reserved. Attribution Statement: © Environment Agency copyright and/or database right 2015. All rights reserved.

Images of the topography of Australia (DTM) have been created from a digital data file of about 320 000 topographic spot heights measured during the gravity survey of Australia, resampled on a …Show full descriptionImages of the topography of Australia (DTM) have been created from a digital data file of about 320 000 topographic spot heights measured during the gravity survey of Australia, resampled on a regular grid , and manipulated with a Comtal image analysis system to enhance topographic features. Three manipulations: pseudo-colour transformations, bit-plane images, and synthetic reflectance images are illustrated and discussed to give an idea of the range of computer techniques that can be used to enhance continental topography for geologic or related study. Improvements are inevitable in this new technique, which is applicable to any regional data that can be digitised, such as magnetic, gravity, or radiometric data.

The LIDAR DTM (Digital Terrain Model) Time Stamped Tiles product is an archive of raster elevation data produced by the Environment Agency. Site specific LIDAR surveys have been carried out across England since 1998, with certain areas, such as the coastal zone, being surveyed multiple times. Data is available at varying resolutions of 25cm, 50cm, 1m and 2m, depending on project requirements. The DTM (Digital Terrain Model) is produced from the last return LIDAR signal. We remove surface objects from the Digital Surface Model (DSM), using bespoke algorithms and manual editing of the data, to produce a terrain model of just the surface. Available to download as GeoTiff rasters in 5km zipfiles, data is presented in metres, referenced to Ordnance Survey Newlyn and data aligned to the OS Grid. All LIDAR data has a vertical accuracy of +/-15cm RMSE. The transformation used on the data is specific to the time period of survey. Please refer to the metadata index catalogue which show, for any location, what time stamped data is available, the specific dates of survey, resolution of product and what transformation and geoidal model used. Attribution statement: © Environment Agency copyright and/or database right 2020. All rights reserved.

The Digital Land Model (DTM) was derived from the LiDAR (Light Detection and Ranging) survey carried out on 17 May 2022 on the entire urban area of Ferrara, as part of the Experimental Programme of Actions for Adaptation to Climate Change in the Urban Area (Ministry of the Environment and Energy Security). The DTM has a ground resolution of 1x1 m and is available in the geographical reference system EPSG:7791; each cell of the DTM has a numerical value (Band1) corresponding to the share of the land above sea level - The acquisition took place by air flight performed by the company AVT Airborne Sensing Italia, with Riegl VQ780II-S laser scanner sensor of the company Riegl Laser Measurement Systems GmbH. The raw 3D point cloud produced by LiDAR was aligned and georeferred with centimeter precision thanks to the use of 3 x 3 point grids measured on the ground with topographic surveys. The points were classified into points on the ground and above ground with a combination of commercial software and algorithms implemented in AVT. The points classified as ground were checked, filtered and interpolated in a grid to obtain the DTM in raster format. The quotas have been transformed from ellipsoid to orthometric through the use of geoid oscillating grids provided by the Military Geographic Institute of Florence.

Abstract High resolution topography (HRT) surveys is an important tool to model landscapes, especially in zones subjected to strong environmental changes, such as Antarctica, where landform is highly influenced by cryoclasty and permafrost melting. The aim of this work was to obtain a high accurate DTM for Keller Peninsula, Maritime Antarctica. The survey study was assessed in the 2014/2015 and 2015/2016 during the austral summer, by using Terrestrial Laser Scanner (TLS). In order to cover 8 km² of the Peninsula, the TLS equipment was installed in 81 different points. Results of the DTM generated by TLS (hereafter, HRT-DTM), and the terrain variables Aspect, Slope and Hillshade obtained were compared with previous models generated by aerophotographic survey (hereafter, APG-DTM). RMSE for the HRT and APG-DTM were 0.726 and 2.397 m, respectively. Spatial resolution of the DTMs was 0.20 m. Morphometric variables obtained from the two methods presented visual differences on the thematic maps, especially related to the Aspect. Generalization was the main process, whereas interpolation occurred for the HRT survey, being the process of choice for the APG method. A large number of points are obtained by the TLS, providing a dense cloud of points, spatially well-distributed, enabling the generalization process to obtain surface models with high performance.

Abstract In the light of the technological transformations that have been occurring in the field of Remote Sensing, the objective of this study was to evaluate the feasibility and the quality of the results that could be achieved in the topographic modeling of the terrain with a Remotely Piloted Aircraft Systems (RPAS) survey in open-pit mines. The mining activity imposes the recurring topographic survey of mined and service areas that require volume evaluation in an interval of at least one month. In this context, the expectation of adopting traditional remote sensing methods for surveying, instead of land surveys, has always been great. The restrictions on the adoption of the conventional photogrammetric or airborne laser scanning (ALS) methods were related to the need for recurring surveys, which are never simple with the use of manned aerial platforms. In this context, the RPAS opens a window of opportunity that should not be ignored, being the main reason for the case study reported here. The essential data set of the research results from the direct confrontation between two digital terrain models: the first obtained with the RPAS survey executed in 2016 and another one of the same area obtained by a laser aerial survey performed in 2012, which was considered as a quality benchmark. The results recommended that the implementation of mapping solutions with RPAS consider the quality constraints of the photogrammetry in order to improve final results with the theoretical and operational knowledge that underpin the photogrammetric process.

This web map shows the Digital Terrain Model (DTM) of Hong Kong. It shows the topography of terrain (including non-ground information such as elevated roads and bridges) in 5-metre raster grid with an accuracy of ±5m. It is a subset of open data made available by the Survey and Mapping Office, Lands Department under the Government of Hong Kong Special Administrative Region (the “Government”) at https://DATA.GOV.HK/ (“DATA.GOV.HK”). The source data is in ArcInfo ASCII Grid format and processed and converted to Esri File Geodatabase format and then uploaded to Esri’s ArcGIS Online platform for sharing and reference purpose. The objectives are to facilitate our Hong Kong ArcGIS Online users to use the data in a spatial ready format and save their data conversion effort. For details about the data, source format and terms of conditions of usage, please refer to the website of DATA.GOV.HK at https://data.gov.hk.