NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Richard B. Langley
Date: 2013 Aug 25, 00:30 +0000
| Richard B. Langley E-mail: lang@unb.ca |
| Geodetic Research Laboratory Web: http://www.unb.ca/GGE/ |
| Dept. of Geodesy and Geomatics Engineering Phone: +1 506 453-5142 |
| University of New Brunswick Fax: +1 506 453-4943 |
| Fredericton, N.B., Canada E3B 5A3 |
| Fredericton? Where's that? See: http://www.fredericton.ca/ |
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Sent: Wednesday, August 21, 2013 11:33 PM
To: Richard Langley
Subject: [NavList] Re: Visual satellite position fix
Not a polar orbit, but an equatorial geosynchronous one. Most communication & weather satellites use these. They don’t appear strictly stationary, but they make a figure 8 due to the earth’s precession, I believe. Most satellites need to “station keep” with periodic thruster firings to keep on station, or else they will drift off longitude.
Still, it was amazingly advanced thinking for it’s time.
Paul Dolkas
From: NavList@fer3.com [mailto:NavList@fer3.com]
On Behalf Of Andrew Nikitin
Sent: Wednesday, August 21, 2013 8:13 AM
To: paul{at}dolkas.net
Subject: [NavList] Re: Visual satellite position fix
Frank Reed wrote:
> Have you read "The Brick Moon"? I read the first third or so a few years ago. It's a surprisingly readable introduction to the subject of finding latitude and longitude.
I read the begining of it. Not sure how much, but definitely less then, say, 20%. I have hard time reading the 19-th century literary sources because they seem to use a lot of unknown to me cultural references. "Darmok and Jalad at Tanagra" all over the text.
The navigational part was also not transparent to me at all. As far as I understand, his idea was to put a Brick Moon on Greenwich meridian and keep it there. Let's be generous and forget about perturbations.
Still, satellite in the polar orbit will not remain on the same meridian because of earth rotation and even when put on 23.9344696 hours orbit, its motion will be pretty complex for earth bound observer. I do not see how he could use it for navigation without
acurate clock anyway.
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