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Dan Allen  wrote :

> On Friday, September 5, 2003, at 06:36 AM, Vic Fraenckel wrote:
>
> > Loath as SOME users of this list are to introducing computers into
> > celestial
> > navigation, I would like to find someone that has used the "JPL
> > Planetary
> > and Lunar Ephemerides" data to actually produce a computer almanac. I
> > would
> > like to do so but am not sure how to proceed. I am NOT interested in
> > getting
> > the data via the many excellent Web based systems as accessing the web
> > is
> > NOT practical while at sea.
> >
> > Any enlightenment will be appreciated.

Vic - I have been thinking about the possibility of writing such a computer 
almanac, probably using Java.  If I were to do so, it would start out as 
primarily a learning exercise for me, as I have no practical experience of CN 
and little theory.  I would hope that it could develop into something of 
practical use, and which could be made freely available.

My rather limited searching for other similar tools has found a gap between 
commercial products, and free programs with a more basic interface.  I 
haven't looked very hard, yet, though.


> I got that CD-ROM years ago and found it hard to figure out how to use
> it.
> The simplest way of producing a computer almanac is to code up the
> algorithms given in Jean Meeus' "Astronomical Algorithms" book.  I have
> done this for the sun in the Awk programming language and it is found
> on my web site at:
>
>      http://home.comcast.net/~danallen46/AwkS2K.htm
>


Dan - I recently ordered Jean Meeus' book, and will be interested to look at 
your code in more detail.  I got an error message ("sh: line 1: calc: command 
not found") followed by other (correct-looking) output.  It seems an external 
program ("calc") is being used by the script;  is this publicly available?  
Interesting website, by the way.



Phil

   

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