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Old 03-04-2014, 11:35 AM
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mithrandir (Andrew)
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mithrandir is offline
 
Join Date: Jan 2009
Location: Glenhaven
Posts: 4,161
Quote:
Originally Posted by Poita View Post
I was looking at Solar Noon calculators, which make it easy to align you mount and scope properly..
(Hang a plumb-bob, wait for solar noon, mark the North-South line on the ground where the shadow of the plumb-bob line falls at exactly the time that solar noon occurs. Easy!)
..and found that the suncalc site has improved and made it super easy.

Just put in your town and it gives you the details.

e.g. for Mudgee i just typed in 'Mudgee' and it did the rest.

You can also put your exact location and time if you know it.
e.g.
http://www.suncalc.net/#/-32.5905,14...14.04.03/11:08

So solar noon is at 1:06pm for me today, time to get the plumb-bob out.

Also, another simple trick is to sit the plumb-bob in a glass or bucket of water, stops it moving around with every slightest puff of wind.
Just putting in Glenhaven got the map close enough I could drag the marker to home. Still I prefer http://www.esrl.noaa.gov/gmd/grad/solcalc/ even though you have to either know your lat/lon or drag the map all the way from the USA.
April 1 would have been the perfect day for me. Solar Noon was at 12:00:02 AEST. The paving around the pool is oriented within a degree or two of being NS-EW.
The plumb-bob in the glass is a good idea. Using thicker string helps by making a more definite shadow but makes it more susceptible to wind.

If you want something you can run offline, download astrotools.zip from http://www.ngc7000.org/astrotools/to...al.html#source

Last edited by mithrandir; 03-04-2014 at 11:56 AM.
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