Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
2,049
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Outlier's neighbours of a raster analysis in Python/GIS
Starting with point clouds from various drone flights, I created a 0'1x0'1m cell raster with the DEM of Differences (DoD). Next, in order to clean outliers cells, I calculated the 0'1 and 99'9 ...
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GRASS r.horizon returns nonsense
I am trying to calculate the horizon profile from a point on a mountainside, through the appropriate DTM elevation file and the GRASS function r.horizon.height (via QGIS).
However, the output looks ...
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73
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QGIS DEM (Raster) merge: errors
I'm trying to merge 4 tiles (ASC) of a French 1m digital elevation model.
Files are loaded in QGIS, they bear no errors, value range is coherent.
Merging comes with errors and the result is a raster ...
- 405
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Generating orthomosaic from DEM in Metashape
I'm using Metashape to make a point cloud from georeferenced drone images using the basic workflow (Align photos -> Build Point Cloud). I then export that and align it to a LiDAR cloud we have from ...
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Identifying / digitising small surface features automatically in QGIS
I need to locate small features on a digital surface model (dsm) in qgis and get their coordinates.
I have a field surface with distributed molehills they show up in the dsm but is there a tool that ...
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Generate 3D rendering / DEM from NOAA ENC files?
Is there a way to generate a 3D rendering of the underwater topography lines from NOAA ENC files in QGIS?
I want to take the depth contours and generate a 3D or shaded relief map from this.
I ...
- 3
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54
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Using DEFRA LiDAR dtm-1m to calculate slopes etc in QGIS
I have a shapefile of woodland polygons and want to calulate slope and slope orientation of the polygons.
I am using the LiDAR Composite Digital Terrain Model (DTM) - 1m in QGIS. Available at: https://...
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QGIS Slope: Slope processing tools not working as expected using DEM
I have a NRCS 2M DEM Bare Earth file for which I have already successfully applied the Hillshade and Aspect tools in my QGIS v3.34.1 project (see below).
Now I am attempting to determine slope using ...
- 31
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34
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Using a DEM to elevation data to an existing point shapefile
I have a point layer called air_quality_locations which contain points with air quality and ozone readings across California. I also have a 30m DEM for California. How do I take the elevation data ...
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Filter for south pointing areas from a DEM
I want to get all south pointing areas within a city. These will be the ideal locations for PV-Plants.
I am aware that a DEM is rasterdata and there is not an attribut table like for shape files/...
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QGIS 3D viewer autoupdate frames from temporal controller
I am using QGIS 3.30.3 and I am trying to make a cinematic with the 3D viewer of some flood tiles.
I have a Digital elevation Model and a few flood tiles with temporal information. Using the temporal ...
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77
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DSM to DTM limited by polygon
I am currently struggling with a specific DSM to DTM conversion requirement over a raster dataset in QGIS. DSM was born from photogrammetry and I need to automatically get rid of houses and vegetation....
- 121
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Export DEM file of specific places and import into VBS3
I want to get a DEM file to load into VBS3.
I followed the instruction from the internet that use Google Earth Pro.
Here is the link: The instruction that I followed
But the DEM file I've gotten from ...
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36
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Issues Opening Large DTM File in QGIS - ‘Bad Allocation’, 'Error occurred while parsing element at line 1 column 1' Error
I’m trying to open a large DTM file in QGIS but I’m encountering errors. The data is a DTM 5x5 m map of the Lombardia region. The .ige file is 7.7 GB and the .img file is only 522 KB.
I’ve tried ...
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A 5-feet DEM - what does it mean?
When it says that a particular DEM is say "5-feet DEM" - does it mean that:
The distance between two points when elevation was actually measured (or source data before interpolation) is at ...
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