[Proj] Wikipedia ECEF entry
Gerald I. Evenden
geraldi.evenden at gmail.com
Tue Feb 3 16:48:44 EST 2009
On Tuesday 03 February 2009 3:32:48 pm Jay Hollingsworth wrote:
> As long as people are asking about the term ECEF, I would like to fix
> the definition of ECEF on the Wikipedia page
> but first I want to make sure I'm not wrong. Since every high-school
> student in the world relies on Wikipedia, it would be good for it to
> be close to right.
> The definition says "The z-axis is defined as being parallel to the
> earth rotational axes, pointing towards north". Isn't it actually
> coincident with the rotational axis, rather than being parallel?
> I just created a discussion page under the definition so the world at
> large could comment.
I would if I could figure out how to use the *^%*)%) Wiki system. :-(
You seem to be basically correct except for one item: the moon. The whole
mechanism is one big wobble so I am not sure how true the rotational axis is
with the ellipsoid axis. Of course the ellipsoid gets bent out of shape with
the tides and all, and other pertubations from the sun, etc..
Anyway, I am probably nit-picking.
I remember the time I had to code the formula for tidal attraction in the cgs
system (centimeter-gram-second) and taking the nth power of the sun-earth
distance in centimeters blew the exponent on a DEC System 10. Switching to
The whole religious complexion of the modern world is due
to the absence from Jerusalem of a lunatic asylum.
-- Havelock Ellis (1859-1939) British psychologist
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