I use a satellite view on Google Maps....then turn on google compass to
measure "deviation from N" for a known landmark. It's all deskwork, but
gives you a map marked with a compass heading to save for future
"maintenance".
Gets you within a degree or two.
73,
Kirk KK2Z
See http://googlecompass.com/
Kirk KK2Z
On Wed, Jan 25, 2017 at 4:30 PM, <towertalk-request@contesting.com> wrote:
>
> Date: Wed, 25 Jan 2017 12:57:17 -0700
> From: Richard Solomon <dickw1ksz@gmail.com>
> To: towertalk <TowerTalk@contesting.com>
> Subject: Re: [TowerTalk] Fwd: Finding North (was Strange behavior)
> Message-ID:
> <CAC5FBO8qRWfEUDhxSrJM3mMzWByXdE3aci80h=0+m6okY8+RCQ@mail.
> gmail.com>
> Content-Type: text/plain; charset=UTF-8
>
> I would just get a couple or three
> Boy Scouts over and average the
> results.
>
> 73, Dick, W1KSZ
>
> On Wed, Jan 25, 2017 at 12:37 PM, GARY HUBER <GLHuber@msn.com> wrote:
>
> >
> > -------- Forwarded Message --------
> > Subject: Fwd: Re: [TowerTalk] Finding North (was Strange behavior)
> > Date: Wed, 25 Jan 2017 12:35:36 -0600
> > From: Gary Huber <GLHuber@msn.com><mailto:GLHuber@msn.com>
> > Organization: AB9M
> >
> >
> >
> > As a former Field Artilleryman, I suggest you look at ;
> >
> > http://usacac.army.mil/sites/default/files/misc/doctrine/
> > CDG/cdg_resources/manuals/fm/fm6_50.pdf
> >
> > 5-5 for POLARIS METHOD of determining TRUE NORTH see page 5-10. (at
> this
> > time the accuracy error is about 2 mils with a circle having 6400 mils)
> > For the more accurate Polaris-Kochab method, see pages 5-3 thru 5-9.
> >
> > Even with a declinated magnetic instrument, the declination constant can
> > vary dramatically in areas containing iron ore.
> >
> > For radio work this may be trying to use a precision instrument for rough
> > trigonometry.
> >
> > 73 ES DX,
> > Gary - AB9M
> >
> >
> > -------- Forwarded Message --------
> > Subject: Re: [TowerTalk] Strange behavior
> > Date: Wed, 25 Jan 2017 05:39:21 -0800
> > From: jimlux <jimlux@earthlink.net><mailto:jimlux@earthlink.net>
> > To: towertalk@contesting.com<mailto:towertalk@contesting.com>
> >
> >
> >
> > On 1/25/17 4:12 AM, john@kk9a.com<mailto:john@kk9a.com> wrote:
> > > Some day the magnetic pole will flip to the south pole. This will
> really
> > > change the declination numbers!
> > >
> > > John KK9A
> > >
> > >
> >
> > Go to
> >
> > https://maps.ngdc.noaa.gov/viewers/historical_declination/
> >
> > and select the arctic map, and click the checkbox for "modeled
> > historical track of poles" or "observed pole locations"
> >
> >
> > and you'll instantly see why people are talking about "the poles are
> > going to flip relatively soon"...
> >
> >
> > As a practical matter, in Southern California, where for years the
> > declination sits around 14-15 degrees (magnetic pole to the right of
> > the geographic north), the change was about 0.1 degree/year. So a 10
> > year old topo map would be wrong by a degree.
> >
> > in 1900, the 15 degree line crossed just south of the Salton Sea (which
> > didn't exist then...) and the 16 degree line went through the Channel
> > Islands and Ventura county. In late 70s, the declination in Ventura
> > County was about 14.7 degrees. In 1990s it was around 14.1 degrees, in
> > 2004 about 13.5, in 2013 about 12.8
> >
> > In the middle of the US, (along the agonic line, as it happens, but
> > that's coincidence), the pole is essentially moving straight away, so
> > the declination is changing slowly. in Europe, though, the pole is
> > moving cross ways relative to the line towards true north, so the
> > declination is changing quite quickly.
>
>
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