Dear Pete N4ZR,
Here we go again!
I figure that about now you will be getting static from some poster child
for
anal retentive syndrome about the inaccuracy of the "shadow" method.
Here's some ammo:
I'm a serious amateur astronomer and it is really important to know where
north
is for telescope alignment purposes.
I've got a US Navy celestial navigation program which I've used for
years. (it
runs on DOS so it works......every time, never locks up, never burps or
gives me
messages about how stupid I am....HI!)
Anyway, I looked you up on the DX Cluster's Buckmaster listing and ran
sunrise,
transit (also called solar noon.....the time when the sun is due south)
and sundown
for 22 Sep 2001 at your QTH. You may use these to contrive an offset
from the
times given in the paper.
Converted to EDST:
Sunrise 0700
Transit 1305
Sunset 1908
If you split the difference , you get 1304 as the middle of the day.
OH, THE HORROR!!
I ran a position for the sun at your QTH at 1304 and it is 179.7 degrees.
Or about
3 tenths of a degree from due south. There are several factors that
contribute to this
offset, the most prominent is that the earth has traveled in the orbit
about the sun
during the day.
Another source of joy for the "picky-picky" crowd is the fact that the
sunrise-
sunset times are typically for an airport which may be some distance
away.
Trivial. Perhaps a degree or so......no big deal.
Considering the relatively broad bandwidths of HF and VHF beams, it seems
that
the "shadow" method is PLENTY accurate enough.
Polaris is a pretty good way to find north but this method may involve
climbing the
tower at night. Also, the maximum "error" for Polaris is about 44
arcminutes or
something just less than .75 degree. There are times which can be
predicted
when Polaris is either directly north or south of true north (upper and
lower
culmination) but again, for ham purposes, it is a bit much. Telescope
folk, however
really have to be on the button or things will "drift" out of the field
of view.
Well, have to boogie. Our astronomy club is having a public "star party"
tonight and
I can't wait to wow 'em with my new, fairly big (yup.....size does
matter.....HI HI!!)
refractor.
73
Tim K3HX
Cw Elitist
QRP Snob (except on 160 where I run an amp in a futile attempt to
compensate
for a really short antenna with a really crummy ground
screen..HI!)
Old Fart QRV 1964
20 WPM Extra Since 1986
Draft Dodger Enlisted within weeks of turning 17
Zoomie USAF 66-70
Weekend Warrior OH Air Guard 71-72
On Sat, 22 Sep 2001 08:55:48 -0400 Pete Smith <n4zr@contesting.com>
writes:
>
> Awww.... the true North thread is reborn.
>
> Maybe we can nip this in the bud. Get your local paper and find out
> when
> local sunrise and sunset are. Split the difference. When that time
> arrives, go down to the tower and see which way its shadow points.
> That's
> true North.
>
> 73, Pete N4ZR
>
>
>
>
>
>
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