Identification

Title

LIDAR Composite DTM - 25cm

Abstract

The LIDAR Composite DTM (Digital Terrain Model) is a raster elevation model covering areas of England at 25cm spatial resolution. Produced by the Environment Agency, this dataset is derived from a combination of our full time stamped archive, 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. The composite is updated on an annual basis to include the latest surveys. 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 ASCII 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. A tinted shaded relief, which is an image showing what LIDAR looks like when loaded into specialist software, is also available as a WMS feed. You can also download survey index files which shows, for any location, what Time Stamped survey went into the production of the LIDAR composite. 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 and composites of the best data available in any location. To find out more about LIDAR and the various surface models we produce please read our story map This metadata record is for Approval for Access product AfA458. Attribution statement: (c) Environment Agency copyright and/or database right 2019. All rights reserved. Attribution statement: © Environment Agency copyright and/or database right 2019. All rights reserved.

Resource type

dataset

Resource locator

https://environment.data.gov.uk/DefraDataDownload/?Mode=survey

protocol: DSP:ESRI

name: Survey_Download

description: Survey Download

https://environment.data.gov.uk/spatialdata/lidar-composite-digital-surface-model-dtm-25cm/wms

protocol: WMS

name: LIDARCompositeDTM25cm_WMS

description: LIDAR Composite Digital Surface Model (DTM) - 25cm WMS

https://environment.data.gov.uk/DefraDataDownload/?mapService=EA/SurveyIndexFiles&Mode=spatial

protocol: DSP:ESRI

name: Metadata Shapefile Index Catalogues - Download

description: Download the coverage metadata files

https://environment.data.gov.uk/spatialdata/survey-index-files/wms

protocol: OGC:WMS

name: Metadata Index Catalogues - WMS

description: Coverage metadata files - Web Map Service

https://environment.data.gov.uk/spatialdata/survey-index-files/wfs

protocol: OGC:WFS

name: Metadata Index Catalogues - WFS

description: Coverage metadata files - Web Feature Service

https://support.environment.data.gov.uk/hc/en-gb/sections/360001747351-Survey-Data-Catalogue

protocol: http:

name: Survey_Data_FAQs

description: Survey Data Catalogue FAQs

Unique resource identifier

code

6f59c1ce-cc11-43aa-b11d-e1c3ab43a192

codeSpace

Dataset language

eng

Spatial reference system

code identifying the spatial reference system

http://www.opengis.net/def/crs/EPSG/0/27700

Classification of spatial data and services

Topic category

environment

elevation

Keywords

Keyword set

keyword value

OpenData

Elevation

LIDAR

Mapping

Keyword set

keyword value

mapping

GIS digital format

flood

remote sensing

originating controlled vocabulary

title

GEMET - Concepts, version 2.4

reference date

date type

publication

effective date

2010-01-13

Geographic location

West bounding longitude

-5.7

East bounding longitude

1.8

North bounding latitude

55.8

South bounding latitude

50

Extent

Extent group

authority code

code identifying the extent

http://data.ordnancesurvey.co.uk/doc/country/england

Temporal reference

Temporal extent

Begin position

1998-01-01

End position

2017-09-02

Dataset reference date

date type

creation

effective date

2014-10-01

date type

revision

effective date

2017-05-31

Frequency of update

annually

Quality and validity

Lineage

Light Detection and Ranging (LIDAR) is an airborne mapping technique, which uses a laser to measure the height of the terrain and surface objects on the ground such as trees and buildings. Hundreds of thousands of 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 vertical accuracy of the LIDAR dataset is +/-15cm RMSE.

Conformity

Data format

name of format

Open format | Arc/Info ASCII Grid (AAIGrid)

version of format

Not Applicable

Constraints related to access and use

Constraint set

Use constraints

Open Government Licence

Constraint set

Limitations on public access

There are no public access constraints to this data. Use of this data is subject to the licence identified.

Responsible organisations

Responsible party

organisation name

Environment Agency

email address

data.info@environment-agency.gov.uk

web address

https://www.gov.uk/government/organisations/environment-agency

description: Environment Agency Website

responsible party role

pointOfContact

Metadata on metadata

Metadata point of contact

organisation name

Environment Agency

email address

data.info@environment-agency.gov.uk

responsible party role

pointOfContact

Metadata date

2019-10-11

Metadata language

eng