Trident Guidance System

So the military cannot fire a trident Missile from a submarine towards a target satisfactorily.

I wonder if it is possible to write a guidance program using a Raspberry Pi. The inputs would have to be the current GPS Location (2 fields) and the target GPS Location plus altitude (3 Fields).

I suppose, not being an expert, that from these input values the program would have to calculate the distance to the target allowing for curvature of the earth, and therefore how high the missile would have to go - the apogee.

Another thing that would be needed is a compass to determine the direction of flight.  This possibly can be determined by calculations on two successive GPS readings?  And knowing the orientation of the Missile. How would you know this? That way you would know which side rockets to fire or rudders to control to point it in the right direction.

How many inputs/outputs would you need? If it's anything like my RC-Car then two outputs for each of the north/south rudders and two for each of the east/west rudders, and appropriate inputs to give feedback on the positions of these rudders. Then there is the throttle control for the rocket motors, however that works.

A good start.