Garbled contour map

I tried generating a test contour map with the following commands. I basically followed the guide at

mono /gps/tools/Srtm2Osm/Srtm2Osm.exe -bounds1 47.3751046548669 11.178245544433594 47.512794992578826 11.483802795410156 -step 20 -cat 500 100 -large

java -Xmx6044m -jar /home/ralph/gps/tools/mkgmap-r1637/mkgmap.jar --max-jobs=1 --overview-mapname=contours --series-name=“contour 20100510” --product-id=1 --country-name=Europe --country-abbr=EU --latin1 --code-page=1252 --location-autofill=1 --preserve-element-order --remove-short-arcs=3.3 --show-profiles=1 --net --transparent --gmapsupp --tdbfile --style-file=srtm --nsis /srtm.osm

makensis contours.nsis

The resulting map as viewed with mapsource can be seen at the following link

I got the same result without using this style directory. I also got the same when I downloaded the hgt file from

Why is the map so distorted? What am I doing wrong?

Maybe you’re creating contours of a set of stairs? :stuck_out_tongue:

Did you try to split the SRTM2OSM output before passing it to mkgmap? If it’s sufficiently small to not need to be split, you may be able to open the OSM file in JOSM and see whether it’s OK (in which case the problem will be with mkgmap).

If you’re only making a contour map, and have no other data to process, then you don’t need most of the mkgmap options you’ve used though I doubt that’s the cause of the problem.

I opened it in josm and got the same garbled output.
I used Srtm2Osm v1.8.14.10.

Maybe I should try again using a different version of Srtm2Osm.

I have no idea if the order of the command-line switches for SRtm2osm matters, but for what it’s worth, I have no problem when running commands of the form:

Srtm2Osm.exe -large -cat 100 20 -step 10 -bounds1 10 20 30 40 -corrxy 0.0005 0.0005 -o srtm.osm

I’ve tried your area using Groundtruth and encountered no problems

I found that I had used the wrong hgt files from I think I used the 1" instead of the 3" versions. With the correct files, it works beautifully.
Thanks for your helpful responses. The suggestion of checking the osm file with josm helped narrow it down.