MINIMUF-3: A simplified hf MUF prediction algorithm

MINIMUF-3 is a semiempirical model for predicting the maximum usable frequency (MUF) for hf propagation. It was designed to allow simplified hf propagation predictions to be performed in a near real time mobile, tactical environment. An 80 statement BASIC language subroutine is presented which outputs MUF for arbitrary input values of receiver/transmission position, month, date, time (UT), and solar sunspot number. The program is compatible with existing and newly emerging generations of mini- and microprocessor-based computers. Results of extensive tests comparing MINIMUF-3 against hf oblique sounder data are also presented. The sounder data encompassed 196 path months (4704 test points) of observed MOFS from 23 different hf transmission paths. The overall rms residual error of MINIMUF-3 was 3.83 MHz. The results compared favorably with those obtained from large-scale hf prediction codes that were exercised against the same sounder data set.