Transmission of Pulsed Light Signals from Land to Aircraft.

摘要

Equipment for the generation and detection of high intensity light pulses has been developed. Composed of a transmitter and a receiver, the equipment was designed specifically for submarine-to-air signalling purposes. The transmitter and its operation are described in detail. Special attention is given to the light source, a flashtube which emits a light pulse having an effective duration of 0.65 microsecond and a total peak radiant intensity of about 120,000 watts between 300 and 680 millimicrons. Some experimental data on the detectable horizontal ranges attained during land-to-air signalling are presented along with some visual observations made on the light pulse from the transmitter. Although the angular width of the light pulse beam is only thirteen to twenty-three degrees, signals from the transmitter were detected over a horizontal range of almost four miles at an altitude of 5000 feet. Also the effect on the equipment of maintaining visual security is discussed.