[fitswcs] [fitsbits] FITS WCS Paper V: Time - Draft for Review

[William Thompson]

Lucio Chiappetti wrote:

> (3.6 last sentence "Caution")
> 
>   Does a reference exist for the convention described ?

This convention is incorporated into the most recent version of ISO-8601, which 
already appears in the bibliography.

Since we're already referencing Pope Gregorius, one could also reference the 
work crediting with originating this convention:

Cassini, J., 1740, Tables astronomiques DU Soleil et de la Lune, des Planetes, 
des Etoiles fixes et des Satellites de Jupiter et de Saturne avec l'explication 
et l'usage

Bill



> 
> (4. first para)
> 
>   Any reference for Greenbank convention (currently under review in the
>   convention registry) ?
> 
> (4.1 at the end)
> 
>   Why are JEPOCH and BEPOCH "to be used with great caution" ?
>   Please motivate in text
> 
> (4.2.1 pag. 4 end 1st column)
> 
>   "Any other time scale ... not listed on Table I are instrinsically
>    unreliable ..."
> 
>    Can we draw the conclusion AND THEREFORE THEIR USAGE IN FITS FILES IS
>    FORBIDDEN ?
> 
> (4.2.2 title)
> 
>   mention kwd TREFPOS explicitly in the title section !
>   Or anticipate the "Keyword" \paragraph (is that's it in latex parliance)
>   close to the beginning of the section, to give more emphasis to this
>   rather important kwd,
> 
> (4.2.2 last sentence)
> 
>   any reference for the IAU ellipsoid ?
> 
> (4.2.4 keywords, typo)
> 
>   obviously the sentence in the "Keyword" \paragraph shall mention the
>   time reference DIRECTION not position
> 
> (4.4)
> 
>   what is the "prevailing time unit" ? the one in the TIMEUNIT kwd ?
>   Please define explicitly.
> 
> (5.2.1)
> 
>   There is a prohibition of multiple time reference positions etc.
> 
>   However there is a useful case in which one could have two "parallel"
>   axes of time and PHASE (given an ephemeris) which could reside one
>   along the other, and would benefit of being defined and regulated in
>   this paper.
> 
>   (I'm thinking both of phase 0.0-1.0 for folded light curves as well
>   as of an "unfolded" phase (where the bin after 1.0 could be 1.01,
>   and which could go on for an undefined number of cycles)
> 
> (5.2.2)
> 
>   reference to Lorentz transformations etc. ... is it worth reporting
>   some formulae in the paper ?
> 
> (References)
> 
>   - the latest reference to the FITS standard (IAUFWG 2008)
>     should be replaced by the journal-published reference
>     2010A&A...524A..42P i.e.
> 
>     \bibitem[Pence et al.(2010)]{2010A&A...524A..42P} Pence, W.~D.,
>     Chiappetti, L., Page, C.~G., Shaw, R.~A., \& Stobie, E.\ 2010, \aap,
>     524, A42
> 
>   - although not advocating "Boncompagni 1582" I'm still wondering
>     whether the quotation of the papal bull is respecting the format
>     used e.g. by science historians (surely the first author should
>     be able to ask "in house" to Owen Gingerich for example)
> 
> (table 4)
> 
>    Title should be "RESERVED time scale keywords"
> 
> (table 6 and 7)
> 
>    do not really understand these tables with a degenerate time axis
> 
> (appendix A)
> 
>   In particular A.5; an "authority within IAU" on these matters should
>   be identified and mentioned explicitly
> 
>   Entire appendix could be reformatted "graphically" as a clearer table
>   with acronym, acronym expansion and textual explanation
> 
> And ... best wishes for the New Year to everybody
> 

-- 
William Thompson
NASA Goddard Space Flight Center
Code 671
Greenbelt, MD  20771
USA

301-286-2040
William.T.Thompson at nasa.gov