Aligning the scope and Solar Noon

[Poita (Peter)]

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.

[mithrandir (Andrew)]

Originally Posted by Poita

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

[Poita (Peter)]

Good point, when I moved to the thicker string, I had to use the water method, but that really settled it perfectly.

It really is the easiest way to get aligned, for me anyway, seeing a line on the ground I can mark is easier than fiddling with a compass.
I'm hopeless with a compass...

[ZeroID (Brent)]

Yep, that's how I set up the Ob Pier when I built it. Great idea about the water though.