Doppler navigation[′däp·lər ‚nav·ə′gā·shən]
Dead reckoning performed automatically by a device which gives a continuous indication of position by integrating the speed and the crab angle of the aircraft as derived from measurement of the Doppler effect of echoes from directed beams of radiant energy transmitted from the craft.
i. Dead reckoning performed automatically by a device that gives a continuous indication of position by integrating the speed derived from measuring the Doppler effect of echoes from directed beams of radiant energy transmitted from the craft. Most airborne Doppplers transmit three or four highly directional beams of frequency-modulated continuous-wave energy with a frequency of 8.8 GHz. These beams are directed from the aircraft as shown in the illustration. The Doppler computer analyzes the received reflections of these beams. By integrating the frequency changes of the four beams, the computer can determine the distance the aircraft has moved horizontally and vertically over the ground. The indicator shows the aircraft track, wind velocity, and ground speed.
ii. A system that determines positions based on the Doppler effect of satellite signals.