A couple of years ago, I surveyed the origins of the GPS system in a Sputnik-inspired satellite navigation system that operated using Doppler shift measurements of satellite signals. The TRANSIT or NAVSAT system yielded 100m – 400m location accuracy (accounts vary).
The system included several firsts: the first nuclear powered satellite (Transit 4A) as well as the first satellite damaged in a nuclear blast (Transit 4B damaged by the United States Starfish Prime high-altitude nuclear test in 1962).
Transit was increasingly overshadowed by the superior performance of GPS and ceased operation in 1996.
Here’s a very informative Navy training video dating back to 1967 providing an excellent overview of the system and how it worked.