Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
2,049
questions
4
votes
1
answer
485
views
What does "post to post" mean?
For example, when someone talks about the "post to post" elevation error of a DTM, what exactly are they referring to?
- 63
-1
votes
1
answer
34
views
What type of web service do GMRT and OpenTopography offer?
From what I understand, GMRT and OpenTopography offer web services for DEMs in geotiff format (raster with unique band of 16 or 32bits) whereas OGC web services serve 3 band rasters.
What's the name ...
- 15
0
votes
0
answers
33
views
Find Python library to work with DEM in GeoTIFF format [duplicate]
I'm looking for a library for Python that will allow me to do the following thing:
I have a DEM in GeoTIFF format, and I have a list of points with coordinates in Lat/Lon format. I need these points ...
0
votes
0
answers
45
views
Calculating accurate viewsheds using DSM and DTM lidar data QGIS
I have a question regarding using DSM (Digital Surface Model) and DTM (Digital Terrain Model) data sets to create Zones of Theoretical Visibility.
I used the QGIS Visibility Analysis plugin to create ...
- 1
0
votes
0
answers
20
views
Choose DEM layer as terrain in 3D view using PyQGIS
I saw that many 3D classes and methods have been exposed to PyQGIS so I was wondering if choosing a raster layer as a terrain was now possible. I'm working on QGIS version 3.36.1.
This is the GUI ...
- 15
1
vote
0
answers
39
views
QGIS: Further subdivide sub-catchments based on DEM
I have a DEM and a vector layer with existing hydrological sub-catchments. Is there a way in QGIS to further subdivide the sub-catchments based on the DEM?
- 85
1
vote
0
answers
33
views
How to augment LiDAR/DSM data from 3d models
For a viewshed analysis in QGIS 3.34, the I have LiDAR/DSM geotif files available. I want to modify/augment the DMS layer by adding the height information from 3d models of specific buildings. This ...
0
votes
2
answers
66
views
Importing DTM from WMS
I used a GetMap request to query a DTM layer (French national DTM coverage called RGE ALTI) in GeoTIFF format. However the resulting layer has 3 bands instead of one. My end goal is to visualize it in ...
- 15
0
votes
0
answers
14
views
Information in addition to Raster zonal statistics
I have a layer of polygons and a DSM. I want to know if I can extract average aspect, slope, and elevation statistics all at once in QGIS. I know another software does this but I forgot the name.
- 111
0
votes
1
answer
31
views
QGIS - transfer outcrop pixels from a DEM raster onto another raster surface at a lower level
In QGIS I would like a solution that will transfer pixels from a DEM raster onto another raster surface at a lower level. I am trying to create 2 geological surfaces, one being ground level (GL) and ...
- 49
1
vote
0
answers
37
views
Starting from a DEM raster, is it possible to arrive at a polygonal layer with a slope greater than 30% not in squares?
On this site it is possible to download DEM maps of Italy with an accuracy of 10 meters: https://tinitaly.pi.ingv.it/Download_Area1_1.html
Bringing this raster into QGIS and running the Slope command ...
- 691
0
votes
1
answer
45
views
Raising/lowering extracted contour layer using QGIS
Is there a way to raise/lower an extracted contour layer?
I've scoured the properties panel and have tried to raise/lower "elevation" menu, but when I make changes there nothing happens to ...
- 11
0
votes
0
answers
21
views
DEM update/interpolation algorithm from control points
Context: I have a reference DEM, and Icesat-2 points covering some parts of it. The DEM is from 2012 and the Icesat-2 points range from 2018 to 2023.
Goal: I am looking for a way to 'update' the ...
- 309
1
vote
1
answer
45
views
Using CreateMosaicDataset_management and AddRastersToMosaicDataset_management in ArcPy
I have a standalone ArcGIS Enterprise Server 10.8.1. I am also using ArcPy with Python 2.7.18. I want to publish an Image Service to my server by creating a SD file, given a folder of DEM .tif files. ...
- 25
1
vote
0
answers
69
views
Make a slope-aspect map and create a circular legend for it in QGIS
I'm working on Terrain analysis of my ROI and could compute aspect and slope separately. Although I found a fairly easy tutorial on how to make a slope-aspect raster, I want to know if it's possible ...
- 11