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Fred, a few days ago, you asked:
"Just out of curiosity, what does one of these polynomials look like?"

(I had mentioned previously:
"So you load your computer with this almanac data. It consists of
coordinates in space for every instant of time (actually polynomials which
allow you to quickly reconstruct the position for any instant of time).")

They could be almost anything. It depends on your software and hardware
constraints. If you've got plenty of memory, the polynomials could be as
simple as linear interpolation:
 x(t) = x(t0) + (t-t0)*[x(t1)-x(t0)]/(t1-t0).
That's a polynomial! Similarly for y(t) and z(t). If you have memory
constraints, you might use Chebyshev polynomials or something similar fitted
to a sequence of x(t_i).

 -FER
PS: There was apparently a bug on the google groups side when Fred's message
posted. It was message #4872 but it came through as "[NavList /]". I've
fixed it in the archive. Any of you who maintain your own archives ordered
by message number may want to manually edit the header of that message.


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