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From: Philip Bailey (no email)
Date: Fri Sep 05 2003 - 16:25:57 EDT
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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