Dipole Radiation Angle

Just an on paper, (so to speak), example of how to do the F2 mapping for QSOs, (and why it's more complicated than it appears at first), today.

Let's consider this QSO to Sweden from San Francisco:

Retrieving the F2 height data immediately led me to the conclusion that the mapping app has to work in spacetime, (sadly, that's not a relativistic reference), as opposed to just in sapce. Here's the output of the Pt. Arguello ionosonde for the times around that QSO:

Notice that there is no value for hmF2 (the maximum estimated height of the F2 layer) at the actual time of the QSO. I'll need to work on statistical data selection as a result, but for now, I'm just going to go with 330 km as an estimate of what the height was at the time of the QSO.

Here's what the path along the Earth looked like

Turning on the current implementation of F2 mapping reveals we'll have lots of things to look at

But the reason I'm writing today is that skip coming from underground to go to Sweden :)

Changing the estimated F2 height makes thing better, but only a little. Clearly, the signal skipped more than once.

This post is about determining how many skips were required, and what that means for the resultant angle of radiation for our dipole antenna.

Well, since one skip isn't enough, the next thing to consider is two.

Using the midpoint method already defined in the rm-rnb-history package, I arrived at the first skip peek being located at

55.24556451189041,-110.29305571520665

Mapping that out by hacking the kml file, we wind up with the following. the lowest white line is the incoming skip with the new midpoint listed above.

In reality, the skip is about 167 miles short of its mark. Give that we're not working with laser beams, that's probably fine. Here's another look at the near miss:

I particularly enjoy that the first skip landing sight was covered in seawater, a very good ground.

Tomorrow, the actual math that I should have used. Here's a preview

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