I have a known point in space with a lat,lon,alt. It has a camera with a line of sight and a angle of field of view. I can take the central point and calculate each corner vector of the field of view, but..
How do I calculate the intersection with the earth (not necessarily at MSL) from these 3D lines from a point in space? I already know the height of this intersection, but need the lat/lon.
If the earth was flat and square - then that is simple trigonometry.
But curvature of the earth and rounded longitude lines has me stumped; and I can't find anything on the net that seems to provide a first step..
I will implement the solution in c#.
Any advice from the 3D gurus here?!