Experimental equipment for communication utilizing meteor bursts

Equipment to provide a full-time duplex teletype channel by means of intermittent transmissions during VHF signal enhancements caused by meteor trails is described. The two identical terminals (each contained in a 24-foot trailer) consist of a 3 kw transmitter, receiver, teletypewriter, magnetic-tape storage device, control system, and operation monitoring equipment. The antenna system at each terminal employs four 5-element Yagi arrays. Special techniques are employed in the system to allow reception of weak signals in the presence of the local transmitter signal, at the same time keeping decorrelation between the oppositely directed paths low. Individual meteor bursts are selected on the basis of their amplitude versus time characteristics in an effort to reduce the character error rate. Results of initial field-tests over the 390-mile path between Sterling, Va., and Walpole, Mass., show that present transmissions over this system have an error rate of about 3 percent. Additional work on the control equipment is expected to substantially reduce the error rate.