| 摘要 |
1,233,384. Electromagnetic wave position finding. J. M. LAPEYRE. 11 June, 1968, No. 27749/68. Heading H4D. The distance R of a transmitter 20, Fig. 1, from a receiver 44 is determined by measuring the time interval t, Fig. 2, A, between reception of the parallel edges (separation d) of electromagnetic beams 26, 28, the beams being rotated together at constant angular velocity a; distance R equals d/ta. Transmitter.-A maser 24 affording continuous or pulse waves is utilized, the wavelength being in the range from microwaves to ultraviolet. In the embodiment a beam splitter 32 (which may be a knife-edge prism and two adjustable plane mirrors) provides the beams 26, 28; a turn-table 35 affords continuous beam rotation. A transmitter 37 produces an omnidirectional pulsed radiation on preferably a different wavelength when edge 34 coincides with a reference direction 38 (e.g. controlled by a photo-cell) for azimuth determination. Receiver.-The output of photo-multiplier 46, Fig. 2, A, is shaped, Fig. 2, B; the outputs of units 50, 52, 54 and 56 are shown on Fig. 2, C, D, E, F and G. AND gate 58 output, Fig. 2, H, is substantially of duration t and pulses from clock 62 are counted during that period. The counter is re-set by a pulse, Fig. 2, J, from unit 65. Azimuth determination utilizes the measurement, by counter 74, of the interval between the receipt of a pulse from transmitter 37 and the edge 34 of beam 28; waveform, Fig. 2, G, from bi-stable 56 is fed via differentiator and separator 76 as one input to bi-stable 68. Devices 64, 74 may be five-decade decimal counters with gas-filled tubes for display. |
