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Frank,

Thank you for your kind attention.

I have a couple of old calculators laying about unused, e.g. TI-82 and
HP-28C. Used to have an HP-97 that had programmable cards and a small
printer. I have a small network at home with several machines running
FreeBSD, Linux [several flavors], Novell, SCO, MS Windows [several
flavors], etc..

It'd be nice if I could prototype it on one of those with the intent on
moving it to something portable later.

I've done a little programming but it's not my trade. I have a
familiarity with Fortran, Pascal, Basic, ASM, & C, and would be amenable
to whichever you thought beneficial. I'd be even more pleased at using
any available open code that you regard as being sufficiently accurate
in it's output  :-)  and would prefer using open source compilers, etc..

I'd like to start with an outline of the 'works', modularize it, and see
how it goes. Though it's not something I need fully functional now,
still I don't want it to become a career either.

What's out there that can be bought and at what price ? If it's high
then it would be worth the struggle, maybe, over some time if it doesn't
require abandoning your life  :-)

I really have little idea of the gravity of this undertaking being
unfamiliar with the underlying math, and calculational constraints, etc..

Your opinions/experience/guidance would be happily accepted.

Cordially,
Courtney


Frank Reed wrote:

> Courtney, you wrote:
>
> "I'm interested in possibly programming a calculator to handle some
> navigation calculations to avoid carrying cumbersome tomes and am
> consequently curious as to how astronomers come up with the declination
> numbers, etc.."
>
>
>
> There are parts of this that are relatively easy to calculate and parts
> that are relatively difficult.
>
>
>
> "Relatively easy": refraction and other altitude corrections, sight
> reduction table equivalents, the equation of time, and the GHA/Dec of
> the Sun and stars at moderate accuracy (a few minutes of arc).
>
>
>
> "Relatively difficult": ephemerides for the Sun, Moon, planets, and
> stars accurate to the nearest few tenths of a minute of arc or better.
> "Calculating" these things on a traditional programmable calculator can
> be a bit tricky since these generally have small amounts of RAM. On the
> other hand, if you're willing to consider a more modern device --a
> handheld computer, a palm device, you would probably have sufficient
> memory to simply store the almanac data directly. This is not difficult,
> and it would get you the same accuracy as in the published Nautical Almanac.
>
>
>
> There are a thousand different ways you could go with this. Are you
> interested in the coding? Or are you mostly interested in the final tool
> (if so, there are many commercial options)? Do you want to start with a
> few of the easy items? Or go for the whole ball of wax?
>
>
>
> -FER
> 42.0N 87.7W, or 41.4N 72.1W.
> www.HistoricalAtlas.com/lunars
>


--
s/v Mutiny
Rhodes Bounty II
lying Oriental, NC
WDB5619

   

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