Topband: propagation data

[Carl K9LA]

  All,

The 3Y team, N0FP, N2XE, VE7BS (an excellent measurement of a sunrise 
enhancement), and others (I apologize if I left you out) should be 
commended for their efforts to collect observational data on 
propagation. I encourage people to particiapte in these endeavors to 
gain a better understanding of propagation. FWIW in relation to these 
experiments, Radio Shack makes an inexpensive digital multimeter with a 
PC interface - it will dump the data to your PC with time logging. I'm 
sure there are more sophisticated ways to do this, but for $60 it may be 
an easy way to go if you have an old PC sitting around collecting dust.

I have no doubt that in the next several years we'll end up with a large 
amount of excellent observational data. I think this is the easy step. 
The next step, correlating it to what the ionosphere is doing, will be 
the tough task. That's because our model of the ionosphere (whether it 
be in IONCAP, VOACAP, DX Atlas, W6ELProp, WinCAP Wizard, or whatever) is 
a monthly median model - we do not have a daily model of the ionosphere. 
George Lane of VOACAP fame summed it up best with respect to the 
developers of IONCAP: "I bet their eyes would pop out of their heads if 
they new Johnny-come-latelies are now making daily predictions with 
these averaged models!" That quote is from George, so I'm just the 
messenger here. :-)

We don't have a daily model of the ionosphere because we don't fully 
understand all the variables that make the ionosphere vary on a 
day-to-day basis. That's why we presently have a statistical model over 
a month's time frame. And that's also why we sometimes have to speculate 
(as N0FP said) - all we can do is tie our daily observations to trends 
in our 'average' model. Sure, we have ionosondes running all over the 
world. But the probability of one of them being located exactly where we 
need it is quite low. Additionally, these ionosondes generally don't go 
low enough in frequency to gather any data at night (specifically the E 
and D regions) - which is what I think we really need to help understand 
propagation on the low bands.

Carl K9LA