I just noticed the text you added to your previous post. In it, you stated that...
Quote:
Originally Posted by Rockin Robbins
And that's why you mentioned shooting noon positions. That's much more accurate. Straight up, you don't have to worry about atmospheric refraction. Since you are looking through the minimum thickness of atmosphere, seeing conditions affect you the least they possibly can for that particular weather condition. BUT the time of culmination, when the Sun is highest, depends on your longitude and YOU DON'T KNOW THAT. So you don't know exactly when to look to find the time of local noon. Of course navigators have sneaky and effective ways to deal with that uncertainty;
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That's not exactly right. While it is true that if a body is
directly overhead, at the observer's zenith, you don't have to worry about refraction...this is a rare occurrence. It only happens when the declination of the body exactly matches one's latitude. Any other time, the altitude of a body on the local meridian will be equal to 90° minus the declination plus or minus the observer's latitude (depending on whether they are in the same or different hemispheres.)
You also wrote:
Quote:
Originally Posted by Rockin Robbins
How about explaining how to do a noon sight and how to use that information to develop your longitude? Latitude is a piece of cake. Just measure the altitude of Polaris. If you're being fussy you can use a polar alignment scope to correct for the offset of Polaris from the actual pole, but that's less than a degree. If you're south of the equator then the bet is off!
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I'd be happy to. But it'll have to wait. I need to get some rest before work.
Also, while I was able to see the screenshot from before when you linked to it, I still cannot see any of the images you are posting in-line. I'm not sure if it's a problem on my end or what.