| 摘要 |
PURPOSE:To carry out measurement of bearing rapidly and accurately even when waves are emitted intermittently and for a short period of time by subjecting the action of an automatic phase tracking counter forcibly into a synchronizing relation when its action gets out of the synchronizing relation with the receiving output. CONSTITUTION:The outputs of a pair of loop antennas Aw and An are combined with the output of a sensing antenna As through balanced modulators Mw and Mn, and applied to a receiver R and the arrival direction of radio waves is indicated by the phase angle theta of the signal pulse delivered at every rotational period of the antenna. The input pulse lines from an oscillator O synchronizing with the rotational period of the antenna are repeatedly counted by a reference counter Nm. On the other hand, input pulse lines are applied through a controller Kq to a phase tracking counter Nq, and repeatedly counted and the synchronizing relations between the counting periods and the output signals of the receiver R are compared in a comparator C. The controller Kq is controlled through a controller Kp, and a reversible counter Np by the output of the comparator C. When the above synchronism becomes a predetermined relation, the counting operation of the counter Nq constantly tracks the output signal of the receiver R and hence the tracking operation is carried out stably. |
