A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: Daytime Venus Moon Fix by Pub 208
From: Greg Rudzinski
Date: 2015 Nov 18, 15:54 -0800
Here is one more check-off on the CN exotica bucket list. To attempt on 1 December at Lat. 34° 10' N Lon. 119° 14' W using the natural horizon standing at the seashore. At 08:55:26 PST Venus meridian passage crossed with 09:38:14 Moon exactly on the prime vertical. I expect this to be an elegant fix in both plot and reduction. Sky gods permitting ;-)
From: David Pike
Date: 2015 Nov 18, 13:38 -0800
Greg Rudzinski you wrote: Attached is a daytime Sun, Venus, and Moon fix. Venus and the crescent Moon were very difficult observations through a slight haze. Pre-calculated altitudes and azimuths were needed to preset the sextant. A Tamaya Jupiter with 7x35mm scope was used using a natural horizon at the beach. Sight reduction was done by the Ageton Classic trig log method.
Greg. As four days have gone by and no ones congratulated you on the Sun, Moon, Venus fix on 14th November, let me do so. Achieving such a fix must be on every navigator’s bucket list. Apart from possibly for a professional seaman, finding a day when all three are visible at a suitable cut and with a sea horizon in all three directions happens very rarely, and requires a lot of awareness. In the past, I’ve managed two out of three in the air, but never all three in one go. I’m rather busy at the moment, but one day soon I’m going to use your observations to see how the fix would work out using AP3270, 34°N, ten minute GHAs from the Air Almanac, and MOB corrections. DaveP
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