> but obviously I can't get it from the internet Are you sure?
> still wondering how the GPS could provide a useful value if the modeling is > difficult, varying widely in time and space. If you ignore local quirks like big chunks of iron ore, the magnetic declination is a set of smoothly curved lines on a map. I expect it compresses well so it won't take much space in a ROM. US Map here: http://www.ngdc.noaa.gov/geomag/declination.shtml (lots of other info too) World map here: http://en.wikipedia.org/wiki/Magnetic_declination Also, there is a fancy changes-over-time map down near the bottom. On the other hand, there are places with really strong local magnetic screwups. Navigation charts often have notes on them. I have a map with a note saying the error is 173 degrees. -- These are my opinions, not necessarily my employer's. I hate spam. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
