NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Low Altitude Setting Sun Sight
From: Stan K
Date: 2017 Sep 9, 21:05 -0400
From: Stan K
Date: 2017 Sep 9, 21:05 -0400
With Celestial Tools I got 1.1 Away at standard temperature (50ºF) and 0.6 Away at 70ºF.
Stan
-----Original Message-----
From: Greg Rudzinski <NoReply_Rudzinski@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Sat, Sep 9, 2017 4:50 pm
Subject: [NavList] Re: Low Altitude Setting Sun Sight
From: Greg Rudzinski <NoReply_Rudzinski@fer3.com>
To: slk1000 <slk1000@aol.com>
Sent: Sat, Sep 9, 2017 4:50 pm
Subject: [NavList] Re: Low Altitude Setting Sun Sight
Bruce,
I get 1.2' away using a Palm app. Well done on the observation ! Low altitude observations will do in a pinch. Even sunrise and sunset timed observations without a sextant will get it done. On the ultra low observations there is the chance of abnormal refraction so use caution. I draw the line at about 4°. Anything below this will show an unfiltered Sun in the horizon mirror.
Greg Rudzinski
From: Bruce J. Pennino
Date: 2017 Sep 9, 10:11 -0700Hello:During August I intended to take a normal sun sight, go for a walk, and watch the sun set over Cape Cod Bay. I was delayed by errands and traffic, and arrived at Cooks Brook Beach, Eastham,MA, USA as the sun had almost set. Beach parking lot {at} 41d 51.9 N 70d 0.5 W. I was quite surprised how good the sight came out. For those interested, the data are below. I wondered about the accuracy of the refraction data. The Hs and time data are the mean of two sights ,sun LL.Date: August 19,2017 Height of eye about 14 ft. IC = 0.0Time: 23:09:10 Air temp about 70 FHs = 3 d 35.0 ' (three degrees plus 35.0') I normally avoid sights below 8-10 degrees. Knowing the latitude, a time sight calculation gives good longitude.Best regards to all.Bruce
