11
votes
Accepted
Filter for south pointing areas from a DEM
You can calculate Aspect to get a raster with values ranging from 0-360º, then reclassify south facing values to 1, and the rest to 0/Nodata.
I use 150-210 as the definition of south:
First part of ...
- 76.3k
6
votes
Accepted
What does "post to post" mean?
Post means simply an elevation point. You can find a definition for example from the GDIWG standard
https://portal.dgiwg.org/files/?artifact_id=11998&format=pdf
post The locations of the ...
- 68k
5
votes
Accepted
QGIS smooth mapzen DEM to create a very simplified topographic map
Solution 1: Discrete layer Styling
Simply create the effect using layer style: set it to singleband pseudocolor, choose a white to black color ramp and manually classify depending on the elevation ...
- 73.8k
5
votes
Accepted
130 TIF DEM file (total size 3 GB) become 7.4 GB TIF file after merging. Why?
Most times when raster processing output is a lot larger than the raster inputs, the cause is different compression settings. Namely, the input rasters used significantly stronger compression than the ...
- 8,316
4
votes
Points-Elevation from DEM via WMS
WMS layers are generally rendered images and seldom contain raw data. Instead of using WMS, download freely available DEM data like ASTER, SRTM or Cartosat. Load this in your project along with your ...
- 163
4
votes
4
votes
QGIS DEM to elevation Points, pixels not centred
I have made an error. Before running the pixels to points tool, I clipped the raster by a mask layer to reduce processing. The clipped raster had a different cell placement to the original, which is ...
- 89
3
votes
Issue with delineation using dem because of a DAM
Gokul is correct in that filling the artefact depression created by the dam would be suboptimal as it would modify every DEM value upstream of the dam up to the spill point, which will affect your ...
3
votes
QGIS: Set two raster to the same height
If you need to do that just once, a rather simple way is to copy one of the DEM files with gdal_translate by using scaling https://gdal.org/programs/gdal_translate.html#cmdoption-gdal_translate-scale
...
- 68k
3
votes
QGIS point sampling misses data on edge of raster (possible bug?)
It's not just the bottom row, it's the right side points as well.
And this is not really a bug, it's just the way raster indexing works. It affects other software as well.
Rasters are indexed top ...
- 67.9k
2
votes
How to extract DEM (Digital Elevation Model) from 3D model
A second solution, which seems more efficient to me, after hours trying to achieve something with the same initial purpose (extraction of a DEM from a mesh constructed with Sketchup [in order to use ...
- 43
2
votes
Raster map tips in QGIS?
I used this formula for the map tip on a DEM layer:
[% round(raster_value(@layer_id, 1, @layer_cursor_point), 2) %] m
It takes the current layer, band 1, at the mouse cursor position and returns the ...
- 259
2
votes
Way of creating "fake" DEM data in QGIS
The SAGA gis toolkit has some commands for generating raster grids via various methods. For example, you can generate some sort of Gaussian noise grid:
using the SAGA command:
saga_cmd ...
- 65.6k
2
votes
Accepted
When loading a DEM in Google Earth Engine, it doesn't load the full map extend
As pointed out by @JonasV, it's the data. SRTM only covers the globe from 56°S to 60°N as shown here and described here:
- 681
2
votes
Accepted
QGIS Drape (set Z value from raster) to set Z-value along all pixels under a geometry (not only vertices)
You can:
Buffer the line with a small distance, like the pixel size*2
Clip the raster with the buffer
Raster pixel to points
Shortest line between features, points as source, input line layer as ...
- 76.3k
2
votes
Points-Elevation from DEM via WMS
As others have stated, obtaining elevation raster datasets is your best bet (and I would say fastest option). Depending on the region of the world you are working in, there are a variety of elevation ...
- 48
2
votes
Accepted
Aligning two orthophotos with Metashape
This approach is unlikely to provide you with useful information. The surfaces and orthomosaics built by Metashape would have both exploited the positional data of the drone at the time of image ...
- 10.2k
2
votes
Accepted
Importing DTM from WMS
By the documentation https://developers.google.com/earth-engine/datasets/catalog/IGN_RGE_ALTI_1M_2_0#bands there are 3 bands in the dataset, and the height in meters is stored into the first band.
...
- 68k
2
votes
Accepted
Using CreateMosaicDataset_management and AddRastersToMosaicDataset_management in ArcPy
These lines...
# Local paths
inputFolderPath = r".\Input" # The folder of imput images
workspacePath = r".\Workspace" # The folder for (mosaic) dataset and geodatabase
...
- 8,446
2
votes
Why is there a difference between Raw and Rendered results?
What you expect as a result, beyond an explanation of the difference between RAW/Rendered is not really clear.
In short, if you save as Raw, what you save remains a DEM, if you save as Rendered it ...
- 3,402
1
vote
Accepted
Combine Slope and Aspect of a DEM for suitiable PV-Powerplants
The procedure is the same as in the answer you reference above, you just need to calculate the "slope" raster out of the DEM and reclassify values <= 1° to 1 and all others to 0.
- 841
1
vote
Load granule subset (tiles) from mosaic based on shapefile footprint (grid) with QGIS
I would build overviews for all rasters (for quicker drawing) then create a vrt.
If you just want to add a subset from a selection you can use pyqgis. Not an easy way but very efficient:
import os
...
- 76.3k
1
vote
How to replace bathymetry in a DEM
I just tried using the gdal:merge tool, and it worked. The order in which you add the files is important. This question https://stackoverflow.com/q/75202479 says that it takes the last value that is ...
- 5,197
1
vote
ArcGIS JS API RasterShaderReliefRenderer does not color full range of DEM elevation values
This is not really a solution, just some findings that show there might be something wrong with the way that RasterShadedReliefRenderer interprets ImageryLayer.
If in ImageryLayer creation instead of ...
- 26.5k
1
vote
Accepted
GRASS r.horizon returns nonsense
r.horizon has been fixed, it will be part of upcoming GRASS 8.3.2 release.
- 901
1
vote
Accepted
QGIS DEM (Raster) merge: errors
Quoting to solution to one of the similar issue: https://gis.stackexchange.com/a/74068/126926 (Quick Summary: You can't write data to a VRT. It's a "Virtual Raster", and is actually just an ...
- 510
1
vote
How to export an IDW DTM as a GeoTIFF file in R
dtm_idw is a SpatRaster from terra. terra::writeRaster does not have format argument. Load terra and remove format
- 9,514
1
vote
Accepted
How to fill pits for a DEM/CHM when using the LAScatalog engine?
What you are trying to do is to apply a custom function on the catalog. This should look like this (not tested)
chm_pit_filled = function(las, resolution)
{
chm = rasterize_canopy(las, resolution, ...
- 9,514
1
vote
Accepted
Separation of DSM as Building DSM and Canopy Height Model in QGIS
One simplistic way to do it would be to add a buffer of approximately two pixel sizes to your polygons. I.e. if your raster data is 1m x 1m then add 2m as your buffer to your polygons. Then repeat ...
- 729
1
vote
Accepted
Enabling render type for Mapzen Global Terrain in QGIS
In QGIS 3.32
Open the Layer -> Data Source Manager menu.
Select XYZ
Select Mapzen Global Terrain
Ensure "URL" is set to "https://s3.amazonaws.com/elevation-tiles-prod/terrarium/{z}/{...
- 67.9k
Only top scored, non community-wiki answers of a minimum length are eligible