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
