Solar Noon

acropolite (Phil) · #1 26-11-2005, 11:57 AM

I have been increasingly using my LX's manual alignment mode and I have never been certain of where true north is, as my usual viewing location is near metal railings and compass readings are useless. Although it's possible to determine true north from the shadow of a stick at solar noon, 12 o clock is rarely solar noon due to variation of longitute within time boundaries. Found this link at noaa to calculate solar noon at any location by inputting your lat/long and time zone. Hopefully if the sun cooperates, I'll be able to get a fix today or tomorriow. BTW the Lat Long have to be negative figures as does the offset to UTC. e.g. Lat -41.23, Long -147.03 Time -10 http://www.srrb.noaa.gov/highlights/...e/sunrise.html

RB (Andrew) · #2 26-04-2009, 05:31 PM

I know this is an old thread but thought it might be helpful to others and I wanted to thank Phil for the link.
After seeing him refer to this thread in another post, I thought I'd try it out and today I was able to permanently mark out 'true south' where I usually setup my tripod.

Should make it quicker to setup and drift align now (until I put in a permanent pier).

Cheers Phil.

Baddad (Marty) · #3 27-04-2009, 03:48 PM

Hey Phil,

Use a plumbob (weight on a string) to align the stick vertically. That will ensure the stick is perpendicular to the 'horizontal ground'.

Cheers Marty

sheeny (Al) · #4 27-04-2009, 04:36 PM

Hey, guys...

My Astroclock will give you solar noon accurate to the second if you enter your longitude.

Hmmm... I remember being asked what use it was... well, this is one!

http://www.iceinspace.com.au/forum/s...ighlight=clock
http://www.iceinspace.com.au/files.html

Al.

RB (Andrew) · #5 28-04-2009, 10:09 AM

Al, could you try both your astroclock and the link that Phil posted and tell me if you get the same result for solar noon at your location.
I used your clock for solar noon and it's off by a few hours (unless I did something wrong).

sheeny (Al) · #6 28-04-2009, 01:09 PM

Quote:

Originally Posted by RB

Al, could you try both your astroclock and the link that Phil posted and tell me if you get the same result for solar noon at your location.
I used your clock for solar noon and it's off by a few hours (unless I did something wrong).

I just did the check, RB. I got good agreement (approx. 1m 33s difference - solar to local - both ways).

Al.