Is there already a solution to this available somewhere? Am I not googling it right? I did come upon solutions for this with a point and plane defined by way of vectors and normals but not points. Have I stumbled upon a blank I can fill? Is there room here for a math paper? My approach is trilateration and averaging of the symmetric (with respect to the plane) solutions. Then simplifying the result. Naturally, I need only calculate the solution for one coordinate axis. The rest will be analogues. Thanks for any advice.