An Evaluation Of Short Term Ionospheric Forecasts For Selected Ssoutheast Asia Dca Trunks

Special short-term, HF, MUF predictions for selected trunks in Southeast Asia were evaluated in the fall of 1966. The evaluation illustrated the problem of predicting the MUF over a short, north-south path in the equatorial latitudes where variations in the MUF up to 8 MHz within a period of several hours are not uncommon. The opportunity to observe HF operations in a military environment led to many interesting conclusions, including the fact that the word propagation is often used interchangeably with outage. Automatic system monitoring and more readily accessible knowledge of propagation effects would assist in minimizing the trunk outages.

"This is a report on a 2-year program of short-term propagation forecast test and evaluation undertaken for the Defense Communications Agency in Southeast Asia. It is essentially the same as the final report to DCA issued as an ESSA Technical Memorandum"--Preface.