#135421 - 06/10/08 04:50 PM
Re: A Challenge with a Question
[Re: wildman800]
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Carpal Tunnel
Registered: 11/09/06
Posts: 2851
Loc: La-USA
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Not to sound rude, but you've all missed the point of the question.
I know how to take an amplitude and find my location via celestial navigation. I've done both for many, many years of open ocean sailing. I know how to find true north during the day or night (nighttime is easier).
The solution mentioned to find north by placing the sun or the moon to your right or left would send you off in the wrong direction, based on my recent observations. Will your observations match mine???
Just try figuring out where true north is and then look to the sun or moon and see if either lines up to a east-sou'east or west-sou'west direction from you, providing that you are in the northern hemisphere, like I am.
By the way, moonset has been a little after midnight in the central daylight savings time zone.
_________________________
QMC, USCG (Ret) The best luck is what you make yourself!
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#135432 - 06/10/08 05:45 PM
Re: A Challenge with a Question
[Re: wildman800]
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Old Hand
Registered: 12/10/07
Posts: 844
Loc: NYC
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If I'm not getting the question, then I'll admit I'm lost.
If one can observe the sun on the horizon, and you whether it is setting or rising, then you should be able to get rough estimate of north (or any direction) based on simply figuring that it is rising or setting in the east or west. As the Sun approaches a solstice, or as latittude increases, these estimates will become less correct. Right now the sun is nearer the solsitce, so it is probably not at least 20 degrees off of direct east or west when observed at sunrise or sunset.
But if you are not quizzing about an amplitude or about the thinking that north will be to the left when one looks at sunrise, then I don't get the question. What are you asking about? You're making me curious. Teach me something.
Edited by Dan_McI (06/10/08 05:46 PM)
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#135457 - 06/10/08 07:48 PM
Re: A Challenge with a Question
[Re: wildman800]
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Old Hand
Registered: 03/01/07
Posts: 1034
Loc: -
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Just try figuring out where true north is and then look to the sun or moon and see if either lines up to a east-sou'east or west-sou'west direction from you, providing that you are in the northern hemisphere, like I am.
Hmm. I see the sunset every evening. Why would it be west-sou'west? It must be west-nor'west during summer. Or you mean "direction from you (me)"? Not from north? Maybe it's about time to replace your compass? It looks like its arrow have reversed magnetic polarity.
Edited by Alex (06/10/08 07:51 PM)
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#135462 - 06/10/08 08:36 PM
Re: A Challenge with a Question
[Re: Dan_McI]
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Stranger
Registered: 02/05/08
Posts: 19
Loc: Central Washington
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On the same note, what direction is shown by the shortest shadow a local noon when using the stick and shadow method of direction finding.
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#135463 - 06/10/08 08:41 PM
Re: A Challenge with a Question
[Re: SHawk]
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Old Hand
Registered: 12/10/07
Posts: 844
Loc: NYC
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On the same note, what direction is shown by the shortest shadow a local noon when using the stick and shadow method of direction finding. Wouldn't that depend on both the observers latitude and the sun's declination?
Edited by Dan_McI (06/10/08 09:08 PM)
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#135464 - 06/10/08 08:49 PM
Re: A Challenge with a Question
[Re: wildman800]
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Carpal Tunnel
Registered: 08/03/07
Posts: 3078
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Hi Wildman800, The azimuth direction where the ecliptic (green line in the picture below) bisects the horizon will depend on the latitude of the observer and time of year. True north will just be the angle you look up from a prepared table added to the azimuth direction. Example; Date 10th June 2008 Latitude 58° 28' N Sunset 22:17 Azimuth direction to sunset 320° 35' degrees Angle between Sunset and true north = 39° 25' degrees
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#135467 - 06/10/08 09:07 PM
Re: A Challenge with a Question
[Re: Am_Fear_Liath_Mor]
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Old Hand
Registered: 12/10/07
Posts: 844
Loc: NYC
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Am Fear Liath Mor, I think that that's pretty much an amplitude.
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#135468 - 06/10/08 09:10 PM
Re: A Challenge with a Question
[Re: Am_Fear_Liath_Mor]
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Carpal Tunnel
Registered: 11/09/06
Posts: 2851
Loc: La-USA
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Being that far North, shouldn't the sun be setting to the west-sou'west???? It sure looks to me like you are seeing a sunset in the northwest while in the northern hemisphere.
By the way, I've been observing a nor'east sunrise and a nor'west sunset (the same is true for moonset) for the last few months. I've been making these observations between the 30N to 41N Latitudes.
It seems to me that the declination is much higher than it should be.
Edited by wildman800 (06/10/08 09:15 PM)
_________________________
QMC, USCG (Ret) The best luck is what you make yourself!
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#135472 - 06/10/08 09:52 PM
Re: A Challenge with a Question
[Re: wildman800]
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Geezer
Registered: 06/02/06
Posts: 5357
Loc: SOCAL
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It doesn't matter much if the sun rises north of east and sets north of west. If you put a stick in the ground vertically and trace the shadow of the tip of the stick, it will form a straight East-West line. A perpendicular line to teh trace will be True North-South. You'll find Polaris on one end, that's North
_________________________
Better is the Enemy of Good Enough. Okay, what’s your point??
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