[LEAPSECS] Equation of time

[François Meyer]

I put here

http://perso.utinam.cnrs.fr/~fmeyer/eot_french.pdf

a scan of the guide to the ephemeris edited by
the french Bureau des longitudes (its in french
but equations translate easily, modulo the coma
as the decimal mark. Down the page, 
M reads 6.240060+6.283019552 t, sorry for the poor 
quality of the scan).

It does not state the estimated accuracy but terms down to 10^-3 mn
are included so it gives an idea. I guess going below that barely
makes sense.

The equation is clearly a fitting "final product", so there 
are no details on the phenomena involved, maybe that
can be found in books like those from Jean Meeus

http://en.wikipedia.org/wiki/Jean_Meeus

Regards,

On Thu, 5 Feb 2015, Tom Van Baak wrote:

> Someone asked me about accurate calculations of the equation of time.
> Since it relates to keeping time, leap seconds, and days perhaps
> someone on the list can shed light on it.
>  
> Most graphs of EoT appear accurate to the minute. Is it possible to
> predict the equation of time to the millisecond level? How complicated
> are the equations. What sorts of non-obvious corrections does one need
> to apply at the seconds level or milliseconds level?
>  
> Are the simple formulae given in
> http://en.wikipedia.org/wiki/Equation_of_time valid at this level, or
> is there serious literature that goes into far more detail.
>  
> Thanks,
> /tvb
> 
>

-- 
François Meyer    Tel : (+33) 3 81 66 69 27   Mob : 6 27 28 56 83
Observatoire de Besancon - BP1615 - 25010 Besancon cedex - FRANCE
Institut UTINAM * Universite de Franche-Comte * CNRS UMR 6213 ***