[RFI] Compass Vectors

[Ron Watson]

Back before GPS, I used a compass quite a bit for survey recon.

If you read the bearing from both ends of the line (or a reverse bearing from a point on the line) that will mitigate a lot of the local attraction problems. A compass is not an accurate device, even the old Wild T1 compass theodilite varied with the time of day.

If you want accurate, true north vectors, given position date and accurate time I can calculate accurate vectors to about 2 arc seconds. I have seen some of the same programs online at solar sales sites but probably only accurate to some like a degree or so.

Ron