Interpreting PropView Graphs
Dave Bernstein <dhb@...>
After generating a prediction for propagation between two locations,toggle quoted messageShow quoted text
check "Show Critical Frequencies" and uncheck "Show Open Bands".
The black curve represents the lowest useable frequency (LUF) as a
function of time. Any frequency lower than the black curve will not
support communications due to absorption.
The blue, green, and red curves provide a statistical range for the
maximum useable frequency (MUF) as a function of time. The actual MUF
will be at or above the blue curve with 90% confidence, at or above
the green curve with 50% confidence, and at or above the red curve
with 10% confidence. Any frequency above the actual MUF will not
support communications, due to insufficient reflection.
So at any specified time, you can identify which frequencies will
likely support communication between the specified locations: they
are bounded on the low-end by the black curve, and on the high-end by
the statistical range between the blue and red curves. You can use
the green curve as a kind of "expected MUF" curve; being an optimist,
I tend to use the red curve for this purpose.
To make it easier to see what ham bands are open when, uncheck
the "Show Critical Frequencies" box and check "Show Open Bands".
Horizontal lines represent ham bands lying between the LUF and
statistical MUF. The thickist lines indicates openings based on the
90% confidence MUF (the blue curve), and the thinnest lines indicate
openings based on the 10% confidence MUF (the red curve).
If you now check "Show Critical Frequencies", the relationship
between horizontal lines and critical frequency curves should be
Suggested corrections, improvements, and/or clarifications to the
above would be appreciated; I'll incorporate the result into the
--- In dxlab@y..., "Richard B Drake" <rich@w...> wrote: