[TowerTalk] Re: Can takeoff angle be too low?

[Pete Smith]

Oops, I accidentally truncated this.  Please look to the end...

At 07:34 PM 12/20/00 +0000, Bill Tippett wrote:
>        Attached is a follow-up from Dean N6BV.  It's too bad
>you can't see his attached files but here is a summary of the Europe
>propagation statistics for GA and AL.  (Yes, I'm in NC but GA is the
>closest QTH to me for which VOACAP statistics are available).
>
>TOA (Degrees)      GA %                 AL % (% do not total 100 due to
>1                   0                   10    visual interpolation errors)
>2                   0                   11.5
>3                   8                   14
>4                  15                   10
>5                  19                   11.5
>6                   8                    9.5
>7                  19                    6
>8                   8                    7
>9                  11                    7
>10                 11                    4
>11                  0                    0.5
>12                  0                    2
>13                  0                    0.5
>14                  0                    1
>15                  0                    0.5
>16                  0                    0.5
>17                  0                    2
>18                  0                    0.5
...

Yes, I *did* read the whole thing.  Fascinating, but nowhere did I see an
answer to the question of why the two arrival angle distributions are so
much different.  Seems counter-intuitive as can be, since the path lengths
and angles to/from Europe don't seem that much different.  It's
particularly striking that Alabama gets so much signal at 1 and 2 degrees,
where Georgia gets nil.  If I were in Alabama, I'd want a recount, since
it's really hard for most folks to do much with such low angles!

I also note that Dean says that these represent arrival angles from "all of
Europe."  Does that in fact mean that it is the sum of arrival angles from
Gibraltar to the Ukraine, and Romania to Norway?  If there are such big
differences in arrival angles in Alabama and Georgia, I would expect much
greater disparities across the geographic range of all of Europe.

73, Pete N4ZR

Contesting is ... Extreme Radio

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