GPS and celnav (and other forms of navigation, radio or otherwise) are really not so different when you get down to fundamentals. At their core they are all abo

GPS and celnav (and other forms of navigation, radio or otherwise) are really not so different when you get down to fundamentals. At their core they are all about locating the intersection of multiple lines, circles, or spheres of position, depending on how many dimensions you're working with. The major differences are in how you come up with the LOPs. The odd man out, if you will, is inertial nav, which has more in common with dead reckoning.