| 摘要 |
PURPOSE:To enable to acquire and trace a loran signal stably over a wide range, by automatically selecting a loran signal excellent in reception state and by using it for the reference of measurement. CONSTITUTION:In a loran A receiver, measurement-reference-station selecting circuit 16 selects a station in an excellent reception state as a measurement reference station. For this purpose, output signals of automatic gain control AGC value circuits 7 and 8 are compared mutually, and output signals of main-station and subordinate-station signal propriety integrating circuit 17 and 18 are also compared mutually; and one station, i.e. the main or subordinate station, having a large difference in AGC value exceeding a constant value and a larger signal propriety integral value is selected as the measurement reference station. In this constitution, when the subordinate station as a tracing station has the AGC value greater than the constant value as the reception position moves even if the main station is assigned to the measurement reference station and the subordinate station to the tracing station, the subordinate station is assigned to the measurement reference station and the main station to the tracing station immediately, so that the loran signal can be acquired and traced stably over a wide range. |
