K1TTT MOF/LOF Propagation Program


Algorithms used in K1TTT MOF propagation prediction program

MOF:
The MOF algorithm devides the prediction up into the following major
parts:
	1. Geophysical and Solar constants
	2. The Ionosphere
		a. Critical Frequency
		b. Height
	3. Path factors

Like most MUF algorithms the basic flow proceeds as follows for a
given path prediction:
	1. Calculate the position of the sun, length of day, time of
		local noon, and solar zenith angle for later use.
	2. Calculate Ionosphere factors based on sun, magnetic
		field constants, polar effects, time and date, etc.
		End result is Critical Frequency, the highest frequency
		reflected for a wave traveling straight up.
	3. Calculate path factors like distance, bearing, number of
		hops, takeoff angle, angle of incidence at the
		ionosphere, etc.  Need locations of reflections off the
		ionosphere, and angle of incidence.
	4. Find the minimum critical frequency at all the hops along
		the path, multiply that by the Path Factor which is
		calculated from the angle of incidence with the
		ionosphere for that path.

Shortcomings of this model.
	1. The ionosphere changes height along many paths so that the
		angle of incidence is not the same at every point.
	2. It does not handle skew paths
	3. It does not handle chordal hops( two ionosphere reflections
		without an earth reflection), E, F1, F-E, etc combination
		hops or ducts.  It only handles basic F2 Layer hops.



LOF:
This is a very simple cos(chi) (chi=solar zenith angle) absorbtion
calculation.