What is difference between DEM DTM and DSM?

Apr. 27, 2023

Digital Elevation Models (DEMs), Digital Terrain Models (DTMs), and Digital Surface Models (DSMs) are three types of digital terrain data commonly used in various fields. While they may seem similar, there are distinct differences between them that affect their applications and uses.

Digital Elevation Models (DEMs) represent the bare earth surface without any of the features on it, such as vegetation, buildings, or other objects. DEMs are derived from remote sensing technologies such as airborne LIDAR, radar, or satellite imagery, which measure the elevation of the earth's surface by bouncing electromagnetic signals off it. DEMs represent a two-dimensional array of grid cells with elevation values, where each cell represents a specific area on the earth's surface.

DEM data is commonly used in various fields such as cartography, geology, and hydrology. It is used for terrain visualization, topographic mapping, hydrologic modeling, land-use planning, and many other applications. The elevation values in a DEM are essential for understanding the terrain and its influence on various processes.

Digital Terrain Models (DTMs) are similar to DEMs, but they represent the bare earth surface after the removal of all vegetation and other above-ground features such as buildings, trees, and other structures. DTMs are created by filtering out the non-terrain features from the raw data used to create DEMs. DTMs are commonly used in terrain analysis and geomorphology studies, where the terrain's shape and form are essential to understanding geological and physical processes.

DTM data is used in fields such as soil erosion studies, slope stability analysis, landform mapping, and many others. DTMs are useful in terrain analysis because they allow for the separation of surface features from the terrain itself, enabling more accurate analysis of the terrain's shape and form.

Additional resources:
Which LCD panel makers offer the best deals for bulk orders?
What is a thick film resistor used for?
What are the different types of LCD panels?
Which TN Fuel Gas Meter Panel Power is the Best for an Efficient Purchase?
Is Lead-Free HASL PCB the Future of Electronics Manufacturing?
What is the cheapest type of resistor?
What is a Leadless package?

Digital Surface Models (DSMs), on the other hand, represent the earth's surface with all the features present, including buildings, vegetation, and other structures. DSMs are derived from remote sensing technologies such as aerial photography or satellite imagery, which capture the earth's surface and all the features present on it.

DSMs are commonly used in fields such as urban planning, forestry, and environmental monitoring. DSMs are useful for visualizing the earth's surface with all its features, providing a more realistic representation of the terrain. They are also used in 3D modeling and virtual reality applications, where a realistic representation of the surface is essential.

One of the main differences between DEMs, DTMs, and DSMs is the way they are created. DEMs and DTMs are derived from remote sensing technologies that measure the elevation of the earth's surface, while DSMs are derived from aerial photography or satellite imagery that captures the earth's surface and all its features.

Another difference is the type of data they represent. DEMs represent the bare earth surface without any features present, DTMs represent the terrain after the removal of non-terrain features, and DSMs represent the earth's surface with all its features present.

The applications and uses of DEMs, DTMs, and DSMs also differ. DEMs are commonly used in cartography, geology, and hydrology, DTMs are used in terrain analysis and geomorphology studies, and DSMs are used in urban planning, forestry, and environmental monitoring.

In conclusion, DEMs, DTMs, and DSMs are three types of digital terrain data commonly used in various fields. While they may seem similar, there are distinct differences between them that affect their applications and uses. DEMs represent the bare earth surface without any features present, DTMs represent the terrain after the removal of non-terrain features, and DSMs represent the earth's surface with all its features present.

For more information please e-mail at frank.zhao@feiyantech.com