NavList:

Apr 29, 2010

Dear Frank,

Although I am going to be very very busy at least until late May, with almost no spare time, I have taken up a few minutes to keep working work on this topic.

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On April 13 th, From: FrankReed---com Re: [NavList 12842]
Date: 13 Apr 2010 17:14 , you wrote :

" I would be interested to see if you can beat my 111 bytes per day (Sun, Moon, 4 nav planets, for one arcsecond accuracy using plain linear interpolation)."

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I started with just the Moon with Ecliptic Longitude Mean Ecliptic / Equator at 24 hour intervals starting from Apr 29, 2010 at 00:00 TT.

For such 24 hour intervals (from 29 APR 00:00.00 TT until 03 May 00:00.00 TT )I get second differences reaching 1366.7", which for mid-interval, would account for a neglected second order term 8 times smaller, i.e. @ 170".

Since the objective is to compute position with just plain LinInt, we would need to restrict the tabular interval well below 1 hour (actually 1 hour gives about 6 " accuracy with just linear interpolation).

So, if we keep "first guessing and reasoning" from the classical LintInt formulae, we would require the Moon Tabular values most probably 4 times/hour, i.e.almost 100 times per period of 24 hours.

This is why I am very surprised that you can achieve all four Nav Planets + Moon + SUN in just 111 bytes per 24 hours, or at least this is my understanding of what you earlier indicated.

You must have some QUITE CLEVER approach, which I would perfectly understand you might prefer to keep un published.

However, I am very curious here simply because your claim here-above has made my mouth water in the sense that I see an opportunity here to learn more on a subject of interest.

Any information on this topic which you feel free to indicate on this forum will be greatly appreciated.

Meanwhile, Best Regards from

Antoine M. "Kermit" Couëtte

PS : I have found a 1" claimed accuracy representation for the Jupiter Heliocentric Coordinates ( R,L,B) which seems to be no more than 10 000 bytes ( 10 kB) in total to cover the entire 2000 year long period [1000 A.D. - 3000 A.D.]. I think this one is, and by far, an all category winner in this respect.

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