IIRC, one can measure the altitude of the sun at local apparant noon (LAN) and
the exact time it occurs. From this data and the equation of time, you can
calc the longitude.Or do the altutude of two different bodies. From each body
one gets a circle of equal altitude on the face of the globe. These two
circles will intersect in two spots. From one's estimated position, one spot
can be eliminated. Therefore the other is the fix.The equations can be solved
by either a calculator equation found in the beginning of the Nautical Almanac
or from tables like Hydrographic Office (HO) 229 for Navy or 249 for Air Force.
The US Power Squadron used to use HO 229; now I believe they've gone calc.I'd
have to refresh since we don't use celestial navigation too much in St.
Louis!RonWild CheriC&C 30STL
--- On Sun, 1/27/13, Chuck S <cscheaf...@comcast.net> wrote:
From: Chuck S <cscheaf...@comcast.net>
Subject: Stus-List Sextant
To: cnc-list@cnc-list.com
Date: Sunday, January 27, 2013, 12:24 PM
#yiv1541387649 p {margin:0;}My understanding is that the sextant measures the
angle between the Moon or Sun and the horizon. If you're careful reading the
solar or lunor tables it gives you the latitude where you are. Longitude is
something else. I know it requires a good timepiece, but how does one convert
the time to longitude?
Chuck
Resolute
1990 C&C 34R
Atlantic City, NJ
From: "Frederick G Street" <f...@postaudio.net>
To: cnc-list@cnc-list.com
Sent: Sunday, January 27, 2013 12:16:33 PM
Subject: Re: Stus-List Mounting chartplotter now Compass Deviation
Pricey little bugger…
I picked up a slightly used Astra 3B several years ago on eBay, from a guy in
Malaysia. Nice wooden box (which I replaced with a Pelican case), and the
thing was smack on for calibration. One thing I did do was to replace the old
incandescent arc illumination lamp with a red LED; it required some redo of the
battery compartment in the handle, but I shouldn't have to change batteries in
a long time.
Of course, it's not much use on Lake Superior -- as big as the lake is, you can
often see the mountains (large hills, actually) on the North and South shores.
I had a chance to run it through its paces on a trip to the Pacific Northwest,
where we actually had a decent horizon to play with. But I'd need to get
familiar with either the paper fix calculation charts or newer celestial nav
software in order to get even remotely proficient again.
Still, it's a cool gizmo to keep around, in case I ever do get out to
bluewater; and it only cost me about $300 plus shipping.
Fred Street -- Minneapolis
S/V Oceanis (1979 C&C Landfall 38) -- on the hard in Bayfield, WI :^(
On Jan 26, 2013, at 8:44 PM, Richard Davis <rdavis2...@me.com> wrote:
Here is a nice metal sextant.
http://www.landfallnavigation.com/-nhu01.html?cmp=pricegrabber&pg=-nhu01&utm_source=-nhu01&utm_medium=shopping%2Bengine&utm_campaign=pricegrabber
_______________________________________________
This List is provided by the C&C Photo Album
http://www.cncphotoalbum.com
CnC-List@cnc-list.com
-----Inline Attachment Follows-----
_______________________________________________
This List is provided by the C&C Photo Album
http://www.cncphotoalbum.com
CnC-List@cnc-list.com
_______________________________________________
This List is provided by the C&C Photo Album
http://www.cncphotoalbum.com
CnC-List@cnc-list.com
