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Re: Online Lunars Calcs
From: Frank Reed CT
Date: 2004 Jun 29, 07:33 EDT
From: Frank Reed CT
Date: 2004 Jun 29, 07:33 EDT
Kieran K asked:
"Can you explain the 6 second of arc potential error."
Probably closer to 1 arcsecond in the almanac data (I believe so at least). But that's more than good enough for lunars. Most other software solutions that I've seen require that the user enter data from the Nautical Almanac. That's not convenient especially for dates more than a few decades in the past. In addition, the ephemeris data for the Moon in almanacs before c.1880 was inherently inaccurate at about +/- 0.3 minutes of arc or more. The ephemeris data at
http://www.HistoricalAtlas.com/lunars
SHOULD be better than those early almanacs (with plenty of caveats -- start naming them!).
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois
"Can you explain the 6 second of arc potential error."
Probably closer to 1 arcsecond in the almanac data (I believe so at least). But that's more than good enough for lunars. Most other software solutions that I've seen require that the user enter data from the Nautical Almanac. That's not convenient especially for dates more than a few decades in the past. In addition, the ephemeris data for the Moon in almanacs before c.1880 was inherently inaccurate at about +/- 0.3 minutes of arc or more. The ephemeris data at
http://www.HistoricalAtlas.com/lunars
SHOULD be better than those early almanacs (with plenty of caveats -- start naming them!).
Frank R
[ ] Mystic, Connecticut
[X] Chicago, Illinois