Positioning system using TV broadcasting from geostationary satellites

As a step to the development of regional positioning systems using geostationary satellites, the authors tried deducing positions of a ship steaming in Tokyo Bay, by making use of three transmitters of TV signals; two geostationary satellites, BS (110/spl deg/E) and Super Bird (162/spl deg/E), and Tokyo Tower (139.75/spl deg/E, 35.67/spl deg/N). The high stability of the synchronous pulses in the video signal makes it possible to find a range more accurately. The RMS error of 240 positions calculated every second on the ship navigating up Uraga Channel is 9.7 m longitudinally and 6.4 m latitudinally in reference to the positions by GPS. But we suspect that the GPS positions might have been modified by the Kalman filter, for the longitudinal error observed at a fixed point (Tokyo University of Mercantile Marine) is as small as 2.9 m.<>