Many thanks Obi One Kenobi ...
Much information and understanding I now have
Morning Dougie ...
Sad I know ... But my interest in stuff like this goes back prior to learning basic Pilot Nav when as a 17 year old A Level Maths stude I wrote a computer programme to resolve Velocity Triangles ... the only problem was that data input was via Marked Sense Cards (using a HB pencil) and Punch Tape with a turnaround of a week to get output back from a computer the size of a mobile classroom ... not very 'practical' ... but I eventually got it to work
40 years ago ...
Best regards ...
Coff.