Re: name the equinox contest on now

From: Markus Kuhn <>
Date: Thu, 29 Jan 2004 12:20:56 +0000

Steve Allen wrote on 2004-01-29 00:13 UTC:
> While the new paradigm of celestial coordinates is rigorously
> defined in terms of mathematics, it is lacking in a common
> terminology. [...]
> [...] the fact is that it is
> difficult to make sense of the proposals without familiarity
> with the past 20 years of literature on coordinate systems.

As a layperson with a good background in mathematics and physics and no
fear of dealing with exact definitions relating to multiple frames of
reference, I tried a couple of times to understand from available online
sources and almanac commentaries the state of the art in astronomic and
terrestrial coordinate systems. I failed each time miserably, thanks to
the -- in my view -- rather inpenetrable use of obscure terminology and
circular definitions.

If someone knows of an introductory tutorial that describes the exact
definition of modern celestial and terrestrial coordinate systems,
without assuming knowledge of any terms other than those of linear
algebra and good high-school-level astronomy, I would be most greatful
for a pointer.

If no such thing exists, then perhaps one of the gurus in the field
might be interested in writing such a tutorial for non-astronomers?
Something comparable to McCarthy's Astronomical Time in Proc. IEEE

Writing such a self-contained tutorial that presents the modern
definitions of earth and space coordinate systems independent of the
past 20 years of literature might also be a valueable exercise towards
coming up with a neat and clean terminology that is free of the
accumulated historic ballast that the current terminology in this field
seems to suffer from.

Perhaps the modern definition of earth and space coordinate systems is
now even ripe for being written up as an ISO standard? The editorial
guidelines of the International Standards Orgainzation strongly
encourage the careful authoring of entirely self-contained
specifications that are practically free of undefined or circular
terminology. So this might be another very useful exercise towards
making this work more accessable and therefore useable by a much larger

Just a thought ...


Markus Kuhn, Computer Lab, Univ of Cambridge, GB | __oo_O..O_oo__
Received on Thu Jan 29 2004 - 04:21:20 PST

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