AZIMUTH-ANGLE MEASURING APPARATUS

摘要

PURPOSE:To output the continuous azimuth angle even when a signal is suddenly fluctuated largely by the effect of the multipaths of radiowaves and the traveling states of radiowaves and even when the radiowave does not arrive temporarily by the effects of the place under a bridge or buildings and to improve the reliability of the measurement of the azimuth angle. CONSTITUTION:An azimuth-angle measuring apparatus has at least two satellite- radiowave receiving antennas 1 and 2 which are provided on a navigating body at a specified distance and a GPS-bearing processing part 3 which processes the azimuth angle of the navigating body by using the satellite radiowaves received with the antennas 1 and 2 and the phase difference between the radiowaves. A straight-advance judging part 8 for judging whether the navigating body is in the straight-advancing state or not is provided. An abnormality detecting part 5 for judging abnormality when the time change in output from the GPS-bearing processing part 3 exceeds a specified threshold value is provided. When the abnormality is judged with the abnormality detecting part 5 and straight advancing state of the navigating body is judged, the azimuth angle immediately before the judgment of the abnormality is outputted.