According to Wikipedia (http://en.wikipedia.org/wiki/Magnetic_declination) Declination converts between true and magnetic bearings: True Bearing equals Magnetic Bearing plus Magnetic Declination. (See http://www.ngdc.noaa.gov/seg/geomag/faqgeom.shtml#q5d). In therion - declination is implemented this way (to avoid confusion), while in survex: (true bearing) = ((bearing)-(declination zero err)) Thanks for pointing out, we will mention this difference in thbook. Regards, S. Quoting Wolfgang Zillig <wolfgang.zillig@web.de>:
Hi,
I've just changed one input file from survex format to therion format to get the LRUD data into the model. The declination is corrected manually by "declination xx degree" within the centreline. I've noticed that I had to change the prefix from "-" (minus) to "+" to get the same result as with survex. In survex it is done by "*calibrate declination xx".
It would be nice to add a comment in the Therion book that declination correction is opposite from Survex.
Regards Wolfgang _______________________________________________ Therion mailing list Therion@speleo.sk http://www.speleo.sk/mailman/listinfo/therion