Questions tagged [dem]
For questions about Digital Elevation Models (DEM), Digital Terrain Models (DTM) and Digital Surface Models (DSM)
330
questions
11
votes
4
answers
12k
views
Determining bare earth DEM from unclassified LAS file?
I have data in LAS format with RGB values created from aerial photogrammetry using a UAV. I am trying to find a solution to extract the bare earth DEM from the point cloud.
I have tried SAGA, ...
- 111
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
114
votes
7
answers
180k
views
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
9
votes
3
answers
8k
views
Normalizing point cloud data
How I can get Digital Height Model (only object heights, DSM - DTM = DHM)?
Many applications can do this, but they convert it to GRID or TIN format. I was wondering if it was possible to keep the ...
- 181
40
votes
4
answers
70k
views
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
7
votes
5
answers
21k
views
Converting LiDAR data to raster (DEM/DSM) for ArcGIS input?
I was wondering if there is an option to convert LiDAR data (.las) to a raster/grid (DEM/DSM) format that ArcGIS 10.0 can read?
- 79
8
votes
2
answers
9k
views
Getting incorrect slope values from an ASTER DEM in QGIS?
I have a DEM layer from ASTER satellite and I want to get the slope information from it.
I use terrain analysis > slope, but the output is so wrong. Why is that?
Here is the DEM:
And here is the "...
- 695
34
votes
6
answers
23k
views
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
14
votes
3
answers
27k
views
Generating DEM from contour Shapefile using QGIS?
I want to create a DEM from depth contours (shapefile) in QGIS. I've been trying to work out how to do this based on this previous question, notably from this link from that page, however I'm stuck, ...
- 1,079
15
votes
2
answers
5k
views
What is the source of horizontal and vertical striping in USGS DEMs?
When processing 30m and 10m DEM data downloaded through the National Map Viewer from the National Elevation Dataset, we noticed horizontal and vertical striping not only in the produced results, but ...
- 2,100
8
votes
5
answers
22k
views
Creating DEM from LAS file without using LAStools?
I want to create a ground model from a *.las file. The LAStools are available in QGIS but limited in use (generation of black diagonal in result file), so I can't use this.
In the GRASS tools I can ...
- 169
27
votes
8
answers
75k
views
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
7
votes
2
answers
23k
views
How to perform a slope analysis in QGIS? [duplicate]
I have contour information in the form of line features (see picture below) and I want to do a slope analysis in QGIS. Is it possible?
- 303
7
votes
2
answers
4k
views
How to de-noise a DSM?
I have created a DEM, DSM, and nDSM from a LiDAR Point Cloud using SAGA-GIS. I extracted the appropriate returns from the point cloud, then converted to grid, and then closed gaps to fill in any ...
- 4,229
8
votes
3
answers
10k
views
Generating STL (3D) file from raster ASTER GDEM data?
I load an ASTER data to Global Mapper workspace and try to export to STL file, receive the message that I need a 3D vector file.
I tried all formats in GM, grid xyz, dem, contour in vector format ...
- 259