POLAR HIGH FREQUENCY RADIO PROPAGATION STUDY.
Final rept. for 1 Mar 63-29 Feb 64,
WASHINGTON STATE UNIV PULLMAN
Pagination or Media Count:
An 18 Mc radio propagation study was conducted using a pulse transmitter and rotating directional antenna at Thule, Greenland, and a fixed directional antenna and receiving system at Pullman, Washington. The 3930 km cis-polar path is perpendicular to the auroral zone, and the zone is about 60 per cent of the distance from Thule. The results showed that the daytime MOF was consistently higher than the CRPL predicted MUF calculated by Gilbert and Hanson especially for this path. Nighttime reception was observed for 10 to 20 per cent of the time during geophysically disturbed periods. The MOF was at least two times the predicted MUF for this reception. Propagation was primarily over the great circle path. However, considerable off-great-circle propagation, attributed either to ionospheric tilts or to higher offcircle MOF values, was observed. Long-delayed pulses, appearing when the antenna main lobe pattern was about 90 degrees, were associated with sunrise-sunset effects. One clear example of forward round-the-world propagation was observed during the four months when data was available. Author