When looking for astronomical data such as the Equation of Time, it is important to choose a data source with an adequate level of accuracy.
It can be worthwhile to have a look at the article "Sun Ephemeris Comparison" published on "Orologi Solari" n. 11 and available in English at the following link: http://www.sundials.eu/download/Comparison%20of%20sun%20ephemeris.pdf This paper shows that one of the best available sources is the Android app "Sol Et Umbra" that can be downloaded for free from the Google Play Store. The same level of accuracy is obtained by the freeware Windows program "Sun Ephemeris" http://www.sundials.eu/download/SunEphemeris_enu.html It can also create a table including the daily EoT values for whichever desired year. It has been correctly underlined that the EoT changes year to year, therefore the above mentioned data cannot be used outside of the year for which they have been computed. When EoT values are required for multi-year use then averaged values should be used. In "Orologi Solari" n. 5 a table has been published by Gianni Ferrari including the averaged EoT values for the years 2014-2061. It is included in the associated digital bonus. Ciao. Gian 2017-04-30 19:46 GMT+02:00 Beverly Stimpson <[email protected]>: > > In message <[email protected]> > Beverly Stimpson <[email protected]> wrote: > > > > > If you need accurate solar 'transit times' (when the sun is exactly > south), > > for any geographic locations (showing CLOCK time corrected for Longitude > in > > a time-zone) for each day of the year, then you could contact Paul Ratto > at > > "SunClocks North America" - E-mail: [email protected] - who can > supply > > these details in the 'PDF' format, (if an Excel spreadsheet in > unsuitable). > > > > Sincerely, > > > > Bev Stimpson. > > > > > In reply to an 'off-list' message I received, (plus to avoid discriminating > against any list-members in the Southern hemisphere) - I have been asked to > mention that a quite similar service (also giving details in PDF format) is > available, showing times when the sun is due NORTH. You can contact George > Marshall, via his website - which is at URL: > www.interactivesundials.com.au > > Sincerely, > > Bev Stimpson. > > > -- > --------------------------------------------------- > https://lists.uni-koeln.de/mailman/listinfo/sundial > >
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