Topband: Topband Propagation

[Robert Brown]

Ford,

What I am proposing amounts to using the control point method, of 
HF propagation, to find the variables which most influence MF
propagation.  But the data is local, small-scale, from above 30 km
altitude.

The HF control point method considers that propagation fails at
one end of a path or the other for the lack of enough ionization
to suppoprt propagation.  As I would apply it in the MF range, I
would consider a path always OPEN from A to B unless a gradient 
tilted the ionosphere and sent signals from A to C, not to B.  The
radiosonde data would then be used to identify the culprit that gave 
rise to the gradient.

Nick, VE7DXR, might be able to do this right now with his data and
radiosonde data from the Victoria/Vancouver airports.  All he'd 
need to do is identify dates when his B.C. stations failed and
get the radiosonde data from their archives.  But at his latitude
there is a possibility of local magnetic/auroral contamination.
A low-latitude transmitter (where the atmosphere is stable) and
a mid-latitude receiving site would be better; but NOT a horde
of beacons all over the place.

BTW, I am quite familiar with radiosondes and ballooning.  I have
launched several hundred scientific payloads on balloons, from the
Arctic to Antarctic.  My balloons were all polyethelyne and reached
a few mB pressure altitude; radiosonde balloons, alas, are rubber
and far less reliable.  So, with luck, 30 km would be an upper limit
But far better than sea-level.

73,

Bob, NM7M