A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: David Pike
Date: 2015 Nov 26, 00:44 -0800
It's too difficult to figure out. No idea where to begin figuring it out. Sam
Sam. Until you give a distance, no one will commit themselves with figures, because they’re frightened of being shot down by a more knowledgeable geographer/mathematician. However, here's a ‘rule of thumb, flat Earth’ navigator’s way of doing it.
If waypoint A is lat 60N 000E/W and you travel 60nm in a direction 060°.
Increase in latitude (northing) = 60nm x Cosine 60° = 60 x 0.5 = 30nm. Therefore, latitude of B = 60° 30’N
Distance travelled east (easting) = 60nm x Sine 60° = 60 x 0.866 = 52nm.
Change easting into minutes of longitude = 52 x Secant 60° = 52 x 2 = 104’ east
Therefore, lat and long of B = 60° 30’N 001° 44’E.
I bet even a dunce like me could turn that into an Excel spreadsheet, but I’m not going to. I’ll leave that up to you. Look after the degrees and the signs (and sines) will look after themselves. E.g. enter 'cosine 240° ' on a calculator, and it'll come up minus automatico. That explains why with some mapping applications on the Internet longitudes don't come up in E & W; they come up in + and minus. DaveP