Optimum HF prediction

The usual HF prediction is based on MUF, maximum usable frequencies, alone. More detailed predictions include LUF, lowest usable high frequency, calculations which indicate the lowest frequency at which the receiver threshold is exceeded at least 50 per cent of the time. The optimum HF prediction presented in this paper provides contours of the probability of successful HF transmission as a function of frequency and time of day. This contour presentation now provides a detailed means for efficient HF spectrum utilization, giving a probability number to any assigned frequency at a given time of day which can be compared to any other available channel probability.