NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Reality check
From: Greg R_
Date: 2006 Jun 6, 15:03 -0700
From: Greg R_
Date: 2006 Jun 6, 15:03 -0700
Red wrote:
> If we start with knowing the sun's rising position and altitude will vary
> by a fixed number of degrees and days, and divide out, we already can
> get some information simply by observing sunrise and noon, no batteries needed.
Well, I can see how that might give you a date (though my example assumes we know that already), and a latitude (which could also be determined within a degree or so without any other references or paperwork by a Polaris shot, at least in the Northern Hemisphere).
> Or perhaps, that topic belongs in another forum, one for "instrument
> free navigation for real celestial navigators"
Yeah, I think the Polynesians were on to something... I may dive into that area once I get my celnav skills up to where I can get consistently good fixes. I got a nice sun/moon cross at the beach over the weekend with 0.2 NM intercepts (to a known GPS position) - don't know if I can pull off that kind of accuracy on a consistent basis, but the Astra is sure proving itself to be a fine precision instrument to work with. :-)
--
GregR
----- Original Message ----
From: Red <hellosailor@VERIZON.NET>
To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Sent: Tuesday, June 6, 2006 10:57:19 AM
Subject: Re: Reality check
> If we start with knowing the sun's rising position and altitude will vary
> by a fixed number of degrees and days, and divide out, we already can
> get some information simply by observing sunrise and noon, no batteries needed.
Well, I can see how that might give you a date (though my example assumes we know that already), and a latitude (which could also be determined within a degree or so without any other references or paperwork by a Polaris shot, at least in the Northern Hemisphere).
> Or perhaps, that topic belongs in another forum, one for "instrument
> free navigation for real celestial navigators"
Yeah, I think the Polynesians were on to something... I may dive into that area once I get my celnav skills up to where I can get consistently good fixes. I got a nice sun/moon cross at the beach over the weekend with 0.2 NM intercepts (to a known GPS position) - don't know if I can pull off that kind of accuracy on a consistent basis, but the Astra is sure proving itself to be a fine precision instrument to work with. :-)
--
GregR
----- Original Message ----
From: Red <hellosailor@VERIZON.NET>
To: NAVIGATION-L@LISTSERV.WEBKAHUNA.COM
Sent: Tuesday, June 6, 2006 10:57:19 AM
Subject: Re: Reality check
""So if I blindfolded you and
dropped you off anywhere in the world, you could figure out where you are just
from celestial?"). "
Greg, I suspect the answer would be "YES!" even
though the position circle might be somewhat larger than ten feet, and a clear
night sky might be of use.<G>
If we start with knowing the sun's rising
position and altitude will vary by a fixed number of degrees and days, and
divide out, we already can get some information simply by observing sunrise and
noon, no batteries needed.
Or perhaps, that topic belongs in another forum,
one for "instrument free navigation for real celestial
navigators".<G>