 The Transit system of navigation consisted of the Transit satellite, a worldwide network of tracking stations to observe and determine the orbital elements of the satellite, and suitable receivers and Autonetics Recomp computers aboard the navigating vessel to receive the stable frequency radio signals broadcast by the satellite, to observe the Doppler frequency shift, and from this information, plus the approximate location of the vessel, compute to within one mile (1.6 km) the exact location of the vessel.The quartz Reference Oscillator was the heart of the shipboard system, and operated at 1 MHz and 100 KC with a short term stability of 5 parts in 10 to the tenth averaged over a one-second interval, and a long term stability of 5 parts in 10 to the tenth per day.The Video Integrator accepted the radar video signal returns from a pulsed, range-gated radar system (AN/FPQ-4) and improved the signal-to-noise ratio of the radar video, thereby extending the acquisition range of the radar system.