A Digital Terrain Model (DTM) can be automatically calculated as a self-service by user and viewed in delair.ai. It is especially useful to remove unwanted ground objects from a scene at a quarry or mine site.
The input required are a Digital Surface Model (DSM), along with areas defined to delimit objects above the ground (trees, vehicles or water bodies) in the DSM, that will be removed to build the DTM by interpolation.
1.1. Mandatory Inputs
- Interpolation Areas
1.2. Optional Inputs
1.2.1. 3D Ground Points
This is a vector file containing 3D points (x, y, z) that will be used as reference points. These points are used by the algorithm in a manner that is somehow comparable to GCPs for photogrammetry; in certain areas (Interpolation Areas), the model will be "forced" to go through these reference points contained inside interpolation areas.
1.2.2. Low Points (2D)
This is a vector file containing 2D points (x, y) which serves to indicate that we already have identified ground at these points in the DSM. The DTM will be matched to these DSM points. 3D points are built from these 2D points using z value from the DSM. In certain ares (Interpolation Areas), the model will be "forced" to go through these DSM points contained inside interpolation areas.
1.3. Missing Inputs
In case your survey does not contain an appropriate input, e.g. missing DSM, you will be notified with message ''No datasets satisfy the criterias" :
2. DTM Generation
Step 1 - Open your Site in delair.ai, select the appropriate Survey, that must contain a preliminary DSM (issued from a photogrammetry processing in delair.ai, or imported)
Step 2 - Go to the analytics catalog from the analytics button on left bar, and open MINES & AGGREGATES section :
Step 3 - Open DTM and press LAUNCH button :
Step 4 - Select the DSM, plus the Interpolation Areas :
Step 5 - Press Next step button :
Step 6 - Input the Buffer size. If you leave the default value (0) unchanged, you indicate to the algorithm that you do not want to apply any buffer.
Step 7 - Press Launch dtm button, then Finish :
3. Progress & Completion Status
You can check status anytime from the analytic LAUNCHED tab.
4. Browsing the DTM
Exiting Analytics section, or from any other section in the platform, follow sequence below :
Step 1 - Go back to Layers section :
Step 2 - Open the BASE LAYERS section and select the DTM :
Step 3 - Clicking on layer will open the information panel on right side; from which you can read the DTM properties, and notably elevation in any point of the map using Value at point tool :
5. Exporting the DTM
In case you need to export for third-party usage :
Step 1 - Go to Downloads section from the left bar :
Step 2 - Select and export your file :