Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
2,049
questions
114
votes
7
answers
180k
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Differences between DEM, DSM and DTM?
I am listing some of the acronyms used in our work and had to stop to think about whether to list these together or separately:
DEM: Digital Elevation Model
DSM: Digital Surface Model
DTM: Digital ...
- 35.8k
59
votes
9
answers
88k
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Choosing colour-ramp to use for elevation? [closed]
This is maybe rather subjective as it concerns style, but I would like to have a few decent colour ramps for my DEM when it is layed over my hill-shading.
I have created the Swiss hillshade model as ...
- 10.2k
48
votes
5
answers
26k
views
Smoothing DEM using GRASS?
I have a SRTM DEM and I want to create a shaded relief from it. I created the shaded relief in GRASS and the result is very nice, but a little rough because the area is near flat and the DEM is 90m in ...
- 9,825
40
votes
4
answers
70k
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Creating DEM from contours in QGIS?
I have a shapefile with contours and their heights.
Is it possible to make a DEM from contours in QGIS without using GRASS?
I found Creating DEM from contours using ArcGIS Desktop? but the answer ...
- 3,444
38
votes
3
answers
7k
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Creating transparent hillshade?
I get elegant transparent hillshades via a combination gdal and convert. Compare to grey-based hillshade commonly used, such transparent hillshades are very cool because they can be placed between the ...
- 2,653
35
votes
2
answers
18k
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LAS to DEM conversion [closed]
I regularly come across LiDAR (.LAS) files with elevation data. When I do, I always struggle to find a way of converting them to a DEM for hydrological analysis. I have developed several workflows, ...
- 4,938
34
votes
6
answers
23k
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Splitting raster into smaller chunks using GDAL?
I have a raster (USGS DEM actually) and I need to split it up into smaller chunks like the image below shows. That was accomplished in ArcGIS 10.0 using the Split Raster tool. I would like a FOSS ...
- 12.7k
34
votes
3
answers
23k
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How to produce high-resolution DEMs from new Sentinel-1 data?
This is a general question relating to the new Sentinel-1 data. I'm interested in the potential for using this data to create high resolution DEMs in GIS (I use QGIS), to investigate archaeological ...
- 779
30
votes
8
answers
8k
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Generating random but believable digital elevation model?
Is there a way to generate a DEM, programatically or otherwise, that will feed into ArcGIS Desktop for further spatial analysis?
Perhaps this needs to be broken down into smaller incremental steps:
...
- 5,411
30
votes
6
answers
16k
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Calculating terrain Curvature in QGIS
I have an elevation raster and I would like to get some basic terrain variables, such as slope, ruggedness, aspect or curvature.
The problem is that I don't seem to have the possibility to calculate ...
- 411
27
votes
8
answers
75k
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Viewing LIDAR data (.las) in QGIS?
Is there an easy path to visualizing LIDAR data in QGIS?
I have some USGS LIDAR data in .las format downloaded from http://lidar.cr.usgs.gov/. This means I have both the .las and metadata in .xml ...
- 606
27
votes
2
answers
44k
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Choosing IDW vs Kriging Interpolation for DEM creation?
I'm trying to create a DEM using point data spaced very regularly about 10m apart. The area I am interpolating is an educational facility with many flat parking lots and football fields but still has ...
- 869
20
votes
5
answers
10k
views
Manually correcting raster DEM (OpenSource)?
Is it possible, to correct a raster DEM by changeing the raster-cell-values manually, like by "painting"?
My DEM (ASTER) have one small error where the elevation is about 300m below the actual ...
- 8,338
19
votes
5
answers
16k
views
Using SRTM Global DEM for Slope calculation
I have downloaded SRTM GDEM (~90m resolution).
I am using ArcGIS 10.
I have tried to use the Spatial Analyst tool to compute for slope.
However, I cannot compute for the slope.
The output values has ...
- 1,188
19
votes
3
answers
3k
views
Account for bridge overpasses in a ground DEM to allow for water flow under the overpass
I have a bare earth DEM made from lidar data (A).
It works well and has passed all accuracy tests. It is used in storm surge models. The problem we are having is on underpasses. I need to allow water ...
