| 摘要 |
PURPOSE:To improve the reception precision of a Decca receiver by inserting an additional pattern with short time width into each transmitted pattern and synchronizing phases of respective transmitted patterns. CONSTITUTION:When the pattern signal receiving circuit 14 of the Decca receiver receives a main transmitted pattern and two slave transmitted patterns, a 90 deg. phase detecting circuit detects a pattern with short time width inserted additionally into each transmitted pattern to discriminated between the main pattern and slave pattern. The circuit 14 is controlled through a timing circuits 13 which reacts to the decision output to select substitute oscillators 16-18 corresponding to patterns to speed up the acquisition of synchronism for received patterns, and then the frequency of the acquisition of synchronism is increased to widen the range of the acquisition of synchronism, thereby improving the reception precision. Consequently, phase measurement precision is improved and a reception position is determined accurately. |
