I've been using viking now for a couple of years on several Windows and Ubuntu PCs but in the last time I'm facing some problems with the DEM information. (now Viking v1.6.2)
If I try to download DEM data using the "DEM Download" button (positioned top right in viking), clicking on the map I get the message "DEM download failure for 48,781394, 9,181004". Coordinate is in central europe.
If I right click on the map to show DEM information, it shows a message that under the link "http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/N48E009.hgt.zip" no file is available
So in the end I don't get any elevation information and don't know where to modify the data source.
I tried to manually download DEM files from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp but I couldn't find out how to properly import them to Viking: .zip package or .tif file? Neither worked in the window to create new DEM layer.
Can anyone help me to get elevation information into my Viking?
Regards,
Tim
Last edit: Tim K 2016-12-31
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Unfortunately the way Viking instructs (lib)Curl to download DEM files defaults to not following any redirects.
If you can compile the code yourself the fix is in the file vikdemlayer.c
Around line 955 change the 0 into number for the number of redirects to follow (e.g. 5).
I'll commit this fix soon and probably look into adding a way to override the default hardcoded SRTM URL parameters to allow using a different service.
Otherwise follow @duizendmiljard advice.
NB Thanks duizendmiljard for your post explaining the issue.
If you would like to refer to this comment somewhere else in this project, copy and paste the following link:
Hello everyone,
I've been using viking now for a couple of years on several Windows and Ubuntu PCs but in the last time I'm facing some problems with the DEM information. (now Viking v1.6.2)
So in the end I don't get any elevation information and don't know where to modify the data source.
I tried to manually download DEM files from http://srtm.csi.cgiar.org/SELECTION/inputCoord.asp but I couldn't find out how to properly import them to Viking: .zip package or .tif file? Neither worked in the window to create new DEM layer.
Can anyone help me to get elevation information into my Viking?
Regards,
Tim
Last edit: Tim K 2016-12-31
Hi Tim,
I think you can't download the files beause the files moved to https in stead of http. When you use wget to get the file:
wget http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/N48E009.hgt.zip
you see a message "URL transformed to HTTPS due to an HSTS policy" and then the file is downloaded from https. Viking uses Curl, and curl doesn't seem to resolve this automaticly:
curl http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/N48E009.hgt.zip
just shows a message that the document has moved.
You can also download the files by copying the url http://dds.cr.usgs.gov/srtm/version2_1/SRTM3/Eurasia/N48E009.hgt.zip in your browser, you will be redirected automaticly. Save the zip file and unzip to get the hgt files. Then in Viking you can add the hgt files in the properties of the DEM layer.
When you start viking from terminal using the -V option "viking -V" you can see what happens.
Unfortunately the way Viking instructs (lib)Curl to download DEM files defaults to not following any redirects.
If you can compile the code yourself the fix is in the file vikdemlayer.c
Around line 955 change the 0 into number for the number of redirects to follow (e.g. 5).
--->
I'll commit this fix soon and probably look into adding a way to override the default hardcoded SRTM URL parameters to allow using a different service.
Otherwise follow @duizendmiljard advice.
NB Thanks duizendmiljard for your post explaining the issue.
Just to note that the fixes are now in the master source code.