INS Alignment
7:45
The usual practice is to slave the aircraft INS to the ships inertial reference. This can be acheived using a cable linking the two systems, or an RF link between the aircraft and the ship.
Modern INS (ring laser) systems linked with GPS can also perform an 'in-motion alignment' including in-flight.
The old mechanical systems are the hardest to manage since you are actually aligning the gimbal rings to orient the platform before the accelerometers are correctly aligned to sense motion.
Very simple but I hope that helps
KM-H