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A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
From: Bill Ritchie
Date: 2025 Apr 6, 14:51 -0700
Thank you, Frank, for your detailed response, and your humour following my ‘feed’ of using NYSE as an example location!
You ask, “What is the actual s.d. of differences?″ Using the same data, with location unspecified, I get 0.38″ for Sun, 0.81″ for Venus, 0.63″ for Jupiter, 0.29″ for Aldebaran and Regulus, 0.24″ for Spica and 0.44″ for Mars. Most were using 25 samples, Mars 14 and Venus 11.
I wanted my software to be able to be used for purposes other than navigation. For example, verifying archaeological statements regarding sunrise azimuths when Stonehenge was built, and visibility of Alpha Centauri from Avebury / Silbury Hill (51° 25’ N) at similar times. A date range of 2999BCE to 2499CE using JPL would take around 500Mb, were such data available.
But, what a good idea for my next update! I could have two versions, the present one for any pyramidologists or soothsayers and a JPL one for our kin.
Bill Ritchie
145nm SWbyW of Stonehenge