Digital terrain model

Encyclopedia : D : DI : DIG : Digital terrain model

---

A digital terrain model (DTM) is a topographic model of the bare earth that can be manipulated by computer programs.

The data files contain the elevation data of the terrain in a digital format which relates to a rectangular grid. Vegetation, buildings and other cultural features are removed digitally - leaving just the underlying terrain.

DTMs are used especially in civil engineering, geodesy & surveying, geophysics, geography and remote sensing. The main applications are:

1. visualization of the terrain (Block diagrams etc.)
2. Calculation of project data or rock masses in civil engineering
3. Reduction (terrain correction) of gravity measurements (gravimetry, physical geodesy)
4. Terrain analyses in Cartography and Morphology
5. Rectification of or satellite photos.

The most usual grid (raster) is between 50 and 500 meters. For several applications [espec. in (1)-(3)] a full resolution is required only for the central areas of the project. Therefore the huge data amount is reduced by a mix of two or three raster spacings.

In gravimetry e.g., the primary grid may be 50 m, but is switched to 100 or 500 meters in distances of about 5 or 10 kilometers.

A digital terrain model may be used to guide automatic machinery in the construction of a physical model, the relief map.

External links

• [DTM data for airborne LIDAR profiles]
• [A rough DTM of Romania]

 

---

From Wikipedia, the Free Encyclopedia. Original article here. Support Wikipedia by contributing or donating.
All text is available under the terms of the GNU Free Documentation License See Wikipedia Copyrights for details.

Search Titles

0

1

2

3

4

5

6

7

8

9

A

B

C

D

E

F

G

H

I

J

K

L

M

N

O

P

Q

R

S

T

U

V

W

X

Y

Z

?