Easy Peasy, Lemon Squeezy Satellite Navigation Using Doppler and Partial Pseudorange Measurements

摘要

Before GPS, there was transit. Also known as the U.S. Navy Navigation Satellite System, Transit was the world's first satellite-based positioning system. It was declared operational in 1968 although it had been in continuous use for the previous five years. The system evolved from the efforts to track the Soviet Union's Sputnik I, the first artificial Earth-orbiting satellite.