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    Re: Low Altitude Setting Sun Sight
    From: Greg Rudzinski
    Date: 2017 Sep 9, 12:57 -0700


    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 -0700


    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 = 0.0

    Time:   23:09:10        Air temp about 70 F

    Hs = 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.


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