# Drillhole Plan Trace in Arc [duplicate]

I'm struggling to find the math to do what I want. I want to plot a top down view of a drillhole in ArcMAP 10.0. I have the beginning UTM coordinate and then for every place in the hole that was measured, a dip (in negative degrees, horizontal being 0), a direction (in degrees, magnetic north being 0, although I can make this true north), and a length or depth.

I would just like to figure out the utm coordinates of each measured station so I can make a polyline. This isn't math I know and although I'm finding lots of information about 3d vector math, I haven't been able to figure out how to translate it to my puproses. So even if someone can tell me how to look for the formulas (what would it be called?) it would be much appreciated. Once I know the formulas, I can use it in Python. Thanks!

• Good find, @Kirk. The only twist is that at each step, you need to look up the magnetic declination of north to make the adjustment from a magnetic bearing to a true bearing. Commented Jun 3, 2013 at 16:47
• Great, that's exactly what I needed to find. I'll add that to a Python script and I should be able to factor in Declination, 100m intervals the ability to handle any direction. Thanks a ton! Commented Jun 3, 2013 at 21:03