Within the program PROPLAB there is a single ray calculation possibility
where you can step through several elevation angles and see which angles are
reflected where.
Look at http://solar.uleth.ca/ for that software.
Gerhard OE3GBB
-----Ursprüngliche Nachricht-----
Von: Andy Cook G4PIQ <g4piq@blacksheep.org>
An: towertalk@contesting.com <towertalk@contesting.com>
Datum: Montag, 15. Dezember 1997 20:46
Betreff: [TowerTalk] Arrival Angles
>We've seen quite a lot of talk on and off about what is the optimum
>height for an antenna of type x to be mounted at, and the answer, quite
>rightly, comes back that there is no substitute for having a variety of
>heights available.
>
>It's seems likely that arrival angles are not static over even short
>periods of time - listening to a signal with QSB on a low and a high
>antenna often shows the QSB to be out of phase between the two.
>
>All the basic propagation prediction software I have seen shows a single
>arrival angle for a particular propagation mode, route, solar
>conditions, month etc. I suspect what we see in reality are signals
>arriving at a variety of angles. Has anyone here any good suggestions as
>to where I can find some software which gives an idea of the
>distribution of angles which we are likely to see over a particular
>path.
>
>I've had a look at VOACAP and didn't find what I was looking for, but I
>may just have been being a bit dumb.
>
>On a similar topic, the folklore of the low bands is that there are
>often nights when the verticals are good and nights when the horizontal
>antennas are good. I've always put this down to differing arrival angles
>between those nights rather than anything fundamental about the arrival
>polarization. Anyone care to comment?
>
>73,
>
>Andy Cook, G4PIQ
>g4piq@blacksheep.org
>
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