Investigation of HF (High Frequency) propagation conditions associated with the third High Energy Astrophysical Observatory Launch

The burning of an Atlas-Centaur rocket in the ionospheric F region was used to determine the extent of HF propagation anomalies associated with the resultant drop in total electron content. This ionospheric hole grew to encompass the control points of many Caribbean of North American high frequency (HF) paths soon after the 0528 GMT launch from Kennedy Space Center, Cape Canaveral, Florida (28.40 degrees N, 80.60 degrees W) on September 20, 1979. Short wave listeners, who collectively monitored 86 paths after launch, volunteered signal strength and fade quality data concerning special broadcasts on 15295 kHz from Bonaire (12.25 degrees N, 68.45 degrees W) and on 17815 kHz from Antigua (17.15 degrees N, 61.82 degrees W).