The NBS Meteor Burst Communication System

This project was undertaken in 1955 to investigate the properties of the intermittent reception of VHF signals over long distances by meteoric propagation and their communication usefulness. To accomplish this, a complete duplex teletype system operating at about 50 mc was constructed, and results are reported from tests made over a 1277-km east-west path. Comparisons are made of burst transmissions of 10, 20, 40, and 80 times normal teletype speed and of varaitions in a number of control system parameters. For the system under test, the optimum speedup was 40X, which produced a daily average channel capacity of about 40 wpm with a character error rate of about 0.0035 (with the best control system settings). Higher speedup ratios are advocated for future systems. The most serious causes of outages in this type of system are atmospheric noise and sustained multipath distortion from competing modes such as E and auroral propagation.