Correct, Optical & GPS; although GPS is not it’s OA... it’s used for tracking or returning to tracking. The GPS isn’t providing OA, the Optical is providing the OA and if needed moves away or detour, and if optical lost, again tracking to return to normal OA flight.
The OA is a plus except when not available. In low light without optics, won’t fly. The GPS can’t assume low light OA.
Agree poor low light OA, sorry I thought we were discussing target acquisition.