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Re: almanac SHA
From: Paul Hirose
Date: 2013 Apr 21, 11:15 -0700
From: Paul Hirose
Date: 2013 Apr 21, 11:15 -0700
Herbert Prinz wrote: > The analysis is based on a critical table of SHA values generated with MICA 2.0. The current version is apparently 2.2.2. I could not find out from the USNO website what the updates are and whether they are crucial to the validity of my test. I have the same MICA version. By trial and error I've determined its precession / nutation model is IAU 1976 / 80 with no frame bias correction. The result is different enough from the current IAU 2006 / 00A model that my Tinyac program has a feature to generate coordinates compatible with MICA. According to the USNO site, the "2000K" nutation model (not an IAU model) replaced the IAU 2000B model in MICA, so the version you and I have is at least two nutation revisions out of date. But in this case the vital point is not which model is more modern, but which one matches the software that computed the Nautical Almanac. I have no idea. -- I filter out messages with attachments or HTML.
