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From: Alexandre Eremenko (no email)
Date: Fri Nov 05 2004 - 22:25:40 EST
Dear Herbert,
I am beginning to suspect that we are just
talking about different things.
I repeat the setting.
We were discussing, say 3 observations of ONE
body's altitude, spread over 5 minutes. You cannot obtain
a FIX from these data. This will be a VERY BAD fix
if you try. To obtain a fix from one body altitudes
you have to SPREAD your observations in time, so that
the azymuth changes MUCH.
From 3 observations spread over 5 minutes you can
obtain ONE position line. Not a fix.
On Fri, 5 Nov 2004, Herbert Prinz wrote:
> I want nothing of the sort. As I said, my equation M * x = a refers to any
> system of linear equations. In the problem in hand, these represent LOPs
> and the solution of the system is the FIX.
> Have you actually looked at the algorithm in the N.A.?
> Have you looked at
> the articles in the Navigation Journal? That's what I am proposing.
Unfortunately, I do not have access to this journal.
And from your messages I cannot determine what situation is
really described in these papers.
Alex.
P.S. Maybe they are talking about observing more than two bodies,
say 3 stars, and how to make a fix from such observations?
I don't think least squares are really needed in this situation,
but certainly people who like computers and do not like
drawing can do this.
But this is a totally different situation from what I was talking
about. I was talking all the time of ONE body
observations over SHORT
time. I never proposed averaging anything else:-)
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