NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bruce J. Pennino
Date: 2013 Jun 22, 13:19 -0700
Hello:
I decided to start this as a new topic. My goal is to see how precisely I can determine my location using my theodolite (read scale to 3 seconds of arc). My thought process: measure zenith angles to celestial body; do a best fit curve; calculate Hs and Ho; using my exact latitude calculate longitude. The closeness of the calculated value compared to the actual value indicates error. As FER says and I think, error should certainly be 1 nm or less.I've redone my calcs again and still get an error or a couple of miles or more depending on which plotted value I use.
Here is the data: 1. All zenith angles with zero degrees straight up. 2. Uncorrected EDT on June 19,2013; watch is 7 seconds SLOW 3. My location is
42d 20.3 N 71d 48.5 W . Holden, MA my driveway. 4. Sighting on moon UL in early EVENING.
Again ZENITH Angles: 59d 53' 44" @ 8:26:55; 59d 48' 51" @8:28:29; 59d 43' 54" @
8:30:16; 59d 40' 30" @8:31:28; and 59d 38' 27 " @8:32:19 EDT evening.
When I do the intercept process, the LOP goes right through my location (as far as I can tell from plot). Something incorrect in my logic or calculation of longitude. Again, moon UL.
Thank you.
Bruce
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