Hi Andrzej, thanks for the hints, I'll have a look at them tomorrow. I think "Spherical versus ellipsoidal model" as a reason is unlikely, the difference should be < 1 %, not ~50% Today I looked at various webpages which calculate the distance between two points, e.g. airports. It is quite funny how different the results are, probably because some are using R=6371 km and others 6378.135 m or values between. Gerd popej wrote
Hi Gerd,
I have looked at your example file in QGIS and Global Mapper and they show distance like JOSM. I don't know why there is so big difference. My guess is that it could be caused by spherical versus ellipsoidal model of the Earth. Maybe you could test algorithms based on Vincenty's formulae? See for example:
http://www.gavaghan.org/blog/free-source-code/geodesy-library-vincentys-form...
http://geographiclib.sourceforge.net/html/java/
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