I take issue with Chris' idea of in-flight alignment.
As far back as 1968 - 1969, the A-7D had both an inertial and a doppler. When coupled, we could get a great airborne alignment given initial launch point for the flight. Then we could select an update fix and refine persent position and all was well. Sometimes we took off and practiced ACM without a full alignment, but the nav system came thru and we were golden after 15 or 20 minutes.
Our prime mode for nav was doppler-inertial, but we had another four modes below that. For example, I flew from Hickam to Guam in the "airmass" mose - TAS and estimated winds plus heading. Had a tanker to fly with, plus 5 other SLUFs. After ten hours I was about 15 miles off. Wish Amelia Earhart would have been that close.
More about the cosmic stuff on the SLUF at the F-16 net site.