Also, my "analemma.bas" DeltaCAD program has options for the analemma on an equatorial dial, choice 2 allows the analemma to be on the dial plate or on the gnomon. Simon
Simon Wheaton-Smith www.illustratingshadows.com Silver City, New Mexico W108.2 N32.75 and Phoenix, Arizona, W112.1 N33.5 --- On Sun, 3/21/10, Brian Albinson <[email protected]> wrote: From: Brian Albinson <[email protected]> Subject: Re: Analemma for Equatorial Sundial To: "Ralf Jung" <[email protected]>, [email protected] Date: Sunday, March 21, 2010, 10:32 AM Ralf The equatorial gnomon analemma dimensions are a function only of the EoT and the dial radius. The longitudinal correction is obtained by rotating the dial hours. There are several ways of implementing analemmatic gnomons, I will send you privately an Excel program which does the calculation. Brian Albinson 3441 Wellington Crescent, North Vancouver BC, V7R 3B3 Phone 604 980 3475 ----- Original Message ----- From: Ralf Jung To: [email protected] Sent: Sunday, March 21, 2010 8:23 AM Subject: Analemma for Equatorial Sundial dear sundial expert's, I want to build a equatorial sundial with a corrector on the gnomon. Like the one at Cosmos Observatory Lasstrop (there is a picture at http://www.fransmaes.nl/zonnewijzers/welcome-e.htm => Pole style:equatorial => armillary spheres netherlands). I read a view articles how to construct this kind of gnomon (e.g. http://www.mysundial.ca/tsp/analemmic_sundial.html). But still there is question which I can not answer. If I construct an analemma (12:00 UT) for the location (longitude 8° 44' E; latitude 48° 35' N) with the ephemeride from the U.S. Naval Observatory then this analemma is tilted to the right sight and not perpendicularly. What are the right numbers to calculate the gnomon-corrector (include longitude)? 1. y = declination; x = EOT + longitude (15°- 8° 44')*4 2. y = declination; x = azimuth from the ephemeride For clarification, my question is not about trigonometry. thanks ralf --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial -----Inline Attachment Follows----- --------------------------------------------------- https://lists.uni-koeln.de/mailman/listinfo/sundial
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