Hi, Here is a topic discussed with a few people during State Of The Map FR last week end in Paris.
Some features mapping would require to tag their azimuth as for knowing how they are really installed in the environment. For instance, benches mapped with nodes may be tagged with azimuth=* because nodes don't tell which direction the bench follows. But how contributors can measure it ? Common devices like smart phones carry compass captors, used by compass applications. These captors only sense the magnetic north to determine the azimuth of the device. The magnetic north is continuously diverting from the geographic north. Using the magnetic north isn't a good idea since the azimuth will be continuously changing instead from the geographic azimuth. There will be the same question regarding standard compasses. Magnetic diversion is mathematically known and such azimuth could be converted into geographic ones. Is there a solution to that issue ? Measuring geographic north directly isn't so simple I think. Cheers. *François Lacombe* francois dot lacombe At telecom-bretagne dot eu http://www.infos-reseaux.com
_______________________________________________ talk mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk

