New answers tagged dem
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To add to what has been said by Michael, I would recommend computing the surface roughness of your DEM using the Rumple index or a simliar metric. You can also perform the roughness estimate on the point cloud itself as long as the ground points have been classified.
You may be able to classify the type of debris you are interested in based on the ...
2
Use the Sample raster values or Add Raster Values to Points tool to extract raster values:
Make sure each line has a unique attribute, eg "Line_ID".
Convert the lines into points
Use the Extract vertices tool if the vertices are frequent enough, or
Use the Points along geometry tool if you want more frequent/evenly spaced sampling points
Use the Sample ...
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Shaded Relief or Hillshade is done from a digital elevation model. You build raster tiles. I've done this with ASTER 2 GDEM and from SRTM. There are tons of methods of accomplishing this however, I find Global Mapper to be the easiest, simplest workflow and fairly quick. Otherwise, use QGIS. Vector Tiles stylesheet is modified to include the raster tile URL ...
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The joy of using the GDAL library is that you never need worry about popular formats again. If a format is at all popular then the will be a GDAL driver for it. Then all you need is to open the raster:
#include "gdal_priv.h"
#include "cpl_conv.h" // for CPLMalloc()
int main()
{
GDALDataset *poDataset;
GDALAllRegister();
poDataset = (GDALDataset ...
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There is probably an easier way, but:
Raster to Point, to get points with value of raster in grid_code field
Select points near the line (to speed up next step)
Generate Thiessen Polygons with Output Field = All fields
Intersect line with thiessen polygons.
You will now have height values for each line segment in the attribute table. If you also want to ...
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Here is one solution using ArcGIS:
1) Resample your 30-meter DEM using the Resample Tool. In the Output Cell Size you can write the path to your 8-meter resolution DEM. For the Resampling Technique choose either Bilinear or Cubic, as they are appropiate for continuous data. Also, before running the tool, click on the Environments... button and click on ...
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This can be done using the
MMQGIS plugin
Once added it will show up in the tool bar at the top of the screen. Select/highland the 'line.data' layer you want to convert to 'points.data'. click on MMQGIS and a drop down will appear. Then click on Modify and then Convert Geometry Type
Then a box appears as seen below -->
Change the 'New Geometry Type' ...
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If you want to add your DEM as a replacement for Google Earth's built-in 3D terrain, unfortunately that's not possible.
That said, there are some options for visualizing DEM data in Google Earth. You can turn your DEM into a raster visualization with techniques like colored shading for the different elevations, or contour lines of some sort. Once you do ...
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Google earth needs KML and KMZ formats for direct uploads.
You can make your DEM an image overlay and manually place it on the area of interest on the map. I linked a resource below that might be helpful to you.
https://freegeographytools.com/2008/creating-google-earth-ground-overlays-from-georeferenced-images
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The filter expression Elio Diaz is describing in the comments can be done via the Con (conditional) tool, either the standalone version or as part of Map Algebra. You would want to follow the examples for complex expressions described here, doing something like this:
Con(dam_layer == NULL, DEM, dam_layer)
(Where there are no dams use DEM, otherwise use the ...
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If you look at the Raster > Analysis > Roughness index in QGIS 3.0, you will see the following (source https://docs.qgis.org/3.4/en/docs/user_manual/processing_algs/gdal/rasteranalysis.html#gdalroughness )
Outputs a single-band raster with values computed from the elevation.
Roughness is the degree of irregularity of the surface. It’s
calculated ...
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