When I was actively flying GPS was just starting to be used by the general aviation community but none of it was certified for landings. It was really nice for navigation purposes though. It was mainly VOR for me and IFR ( I Follow the Road). But GPS is still pretty cool especially after they took out the built in error. I have a hand held GPS unit but to be honest I mostly use it now to verify the speedodmeters on the toys I rebuild. Its very accurate for that.
I dont know but I think it would be a very good idea. If the big one ever breaks out GPS will be targeted and taken out. It could the weapons community. I know the Trident SLBM's use stellar compensated inertial guidance. Buts thats done by onboard computer/gyro's and optics. But thats more of a geek thing than some watch officer on the bridge. They should learn the old/different ways in case they ever needed them. I don't see a down side to them learning it.I understand that the U.S. Navy is recently teaching a smattering of celestial navigation. (I wonder who teaches it?) But what to do when GPS shoots craps? Dead reckoning, visual bearings if near land, and, of course, as a last resort, celestial navigation. I once got a bridge tour on a cruise ship. There was a continuous GPS plot running that I peeked at. It showed that the ship had sailed straight across a island. When I asked about that, they just shrugged and said GPS wasn't perfect. Maybe it was just the chart that was imperfectly imbedded into the software.
The same with me. My flying club started to equip our planes with them. I always considered it as a nice to have backup, not a primary navigational device. Part of the fun of flying, at least for me, was in the flight planning, which included adding in corrections for forecasted winds aloft, and then correcting for actual winds aloft during the flight itself. I do miss those cross-country flights over NJ and PA back in the good old days, and flying up the Hudson river at 1000 ft with the NY skyline along your starboard side. That was before 9/11.When I was actively flying GPS was just starting to be used by the general aviation community but none of it was certified for landings. It was really nice for navigation purposes though.
Ha! If GPS satelites shoot craps or are knocked out by an enemy missile, plot radar ranges and bearings of any nearby terrestrial features. If there are no terrestrial features within radar, then go with dead reckoning from last known position.Pull out your cracker jack box compass...find north then head east or west. You'll run into land sooner or later.
The star sighting is coupled with the inertial guidance data so apparently it only needs one known star fix in relation to its already known position to trim for greater accuracy. But thats all I really now about it. To claim more I would just be blowing smoke. I'm sure the real nitty gritty details are classified. At least I hope so. Its always being changed and upgraded so I'm not sure whats current. And thats just for the missile. I'm not sure how the MIRV'ed warheads are navigated once they leave the missile. I worked on a lot of different missiles. Phoenix, Sparrows, Shrike and Sidewinders. But those are a different field than these. A quick commentary on this subject: I liked my job when I did it. I found the technology facinating. But I wish humanity could go a different direction. Spend the trillions of dollars on something more productive. I know thats just wishful thinking. The world is full of bad guys and must be kept at bay. Only problem is that one good slip up and its Planet of the Apes. I would rather work on Titanics engines.One star sight would only give a line of position, not a fix, right?