Date (Publication)

2007-01-01

Date (Revision)

2022-04-15

Citation identifier

BE.NGI-IGN / 5B217883-3BE6-4626-9B3B-2C1AD391DCA0

Purpose

The National Geographic Intitute uses the DTM primarily as a reference surface for applications at the scale of 1:10 000. It is also used for the internal production of orthophotographs. As a product, it is destined for customers who need a terrain model, wherever in Belgium, with a resolution of 1:10 000 at scale level. As an interpolation of the ground surface, the DTM has a heterogeneous accuracy, which can decline, especially in areas where few or no altimetric data are available.

Status

Completed

Point of contact

Organisation name	Individual name	Electronic mail address	Role
National Geographic Institute		products@ngi.be	Custodian

Maintenance and update frequency

As needed

Data.gov.be themes

• Science and technology

Belgian Federal Thesaurus

• Reporting INSPIRE
• Federal Atom
• Geology and physical relief

Spatial scope

• National

GEMET - INSPIRE themes, version 1.0

• Elevation

GEMET - Concept themes, version 4.01

• relief (land)
• altitude
• federal government
• digital land model

INSPIRE feature concept dictionary

• Elevation Grid Coverage

Use limitation

https://creativecommons.org/licenses/by/4.0/

Access constraints

Other restrictions

Other constraints

No limitations on public access

Use constraints

Other restrictions

Other constraints

https://creativecommons.org/licenses/by/4.0/

Spatial representation type

Grid

Distance

20  m

Distance

5  m

Distance

1  m

Language

Nederlands; Vlaams

Character set

8859 Part 15

Topic category

• Elevation

Description

Belgium

Unique resource identifier

EPSG:3812

Codespace

EPSG

Unique resource identifier

EPSG:5710

Codespace

EPSG

Distribution format

Name	Version
TIFF
Esri Geodatabase

OnLine resource

Protocol	Linkage	Name
INSPIRE Atom	https://ac.ngi.be/remoteclient-open/GeoBePartners-open/ATOM/6657e6da-7345-416f-bef6-c6a8b2def9bd-en.xml	https://ac.ngi.be/remoteclient-open/GeoBePartners-open/ATOM/6657e6da-7345-416f-bef6-c6a8b2def9bd-en.xml

OnLine resource

Protocol	Linkage	Name
WWW:DOWNLOAD-1.0-http--download	https://ac.ngi.be/remoteclient-open/ngi_Inspire_Open/6657e6da-7345-416f-bef6-c6a8b2def9bd_tiff_3812.zip

OnLine resource

Protocol	Linkage	Name
OGC:WMS	https://wms.ngi.be/inspire/dtm/service?request=GetCapabilities&service=WMS&version=1.3.0	INSPIRE WMS

OnLine resource

Protocol	Linkage	Name
WWW:LINK-1.0-http--link	https://www.ngi.be/website/aanbod/digitale-geodata/digitaal-terrein-model/	https://www.ngi.be/website/aanbod/digitale-geodata/digitaal-terrein-model/

OnLine resource

Protocol	Linkage	Name
WWW:LINK-1.0-http--link	https://ac.ngi.be/remoteclient-open/GeoBePartners-open/NGI-IGN/spectech/dtm_spectech_EN.pdf	https://ac.ngi.be/remoteclient-open/GeoBePartners-open/NGI-IGN/spectech/dtm_spectech_EN.pdf

Hierarchy level

Dataset

Dataset

DTM

Statement

The product called ‘DTM’ indicates the height of the ground compared to the Belgian zero level (fictitious zero-D of Uccle). In other words, it is the orthometric height, commonly known as height.

The source data used to produce this DTM are the DTM at a 1m-resolution from the regions: data from Digitaal Vlaanderen (former AIV and former AGIV) for the Flemish Region, data from the SPW for the Walloon Region and data from Paradigm for the Region of Brussels-Capital. These regional DSM are derived from the clouds of points obtained during the LiDAR campaign (flight of 9 October 2021 for Brussels, from 19 February 2021 to 5 March 2022 for Wallonia and from 20 February 2013 to 20 April 2015 for Flanders).

As the Flemish and Brussels regional bodies deliver their products in Lambert 72, the NGI reprojected those in Lambert 2008 and achieved an interpolation in order to obtain a product with round coordinates, and then gathered them with the product of the Walloon Region (already in Lambert 2008) so that the newly created DTM covers the whole Belgian territory.

These source data are gathered and processed in order to obtain a homogeneous and regular grid with every meter a point in X and Y indicating the height of the ground level.

This grid makes the product DTM 1m, i.e. the DTM at a 1 meter-resolution.

This product comes directly from the regional data and is not updated.

The DTM 1m is resampled by bilinear interpolation in order to obtain the same type of grid at a 5m-resolution. This is also improved and updated in-house using direct photogrammetric surveys of points and structure lines based on the most recent aerial photographs in order to create the product DTM 5m.

The DTM 5m consists of a compilation of the best available data, and these are constantly updated and improved.

The product DTM 20m is obtained by resampling through bilinear interpolation of the DTM 1m in order to obtain a grid with a 20m-resolution. This lower resolution makes it a lighter product and allows it to be more widely distributed for all kinds of applications on a national or regional scale.

During the creation of DTM, the highest priority is to get a complete coverage.

The second priority is that the DTM represents the genuine ground level and no other surface (canopy roofs...).

These two priorities meet an important requirement for internal NGI applications and for most external customers.

Besides, the availability of DTM as a standard product (homogeneous and regular point grid) in a generic format (gdb raster file) that can be used by all the software packages is a remarkable asset for internal and external applications.

Description

Each time new source data become available, they are incorporated into the existing source data and checked. On the basis of these new source data, a new version of the DTM is derived.

Description

The different sources which have been used are: image correlation, direct photogrammetric measurement of points and structure lines on the basis of aerial photographs, airborne laser scanning (points), field surveys (points), sometimes completed with linear structures, digitalized, updated and sometimes completed with structure lines.

Metadata

File identifier

6657e6da-7345-416f-bef6-c6a8b2def9bd XML

Metadata language

English

Character set

UTF8

Hierarchy level

Dataset

Date stamp

2024-09-10T09:16:59

Metadata standard name

ISO 19115:2003/19139

Metadata standard version

1.0

Metadata author

Organisation name	Individual name	Electronic mail address	Role
National Geographic Institute	Floor Van Damme	metadata@ngi.be	Point of contact

Other language

Language	Character encoding
French
Dutch; Flemish
German
English	UTF8