Re: Small jumps in inclination

From: NK (
Date: Wed Jul 02 2003 - 13:56:17 EDT

  • Next message: Larry Wood: "Re: Degrees or Arc minutes to Km's"

    Thank you Allen, David and Bjorn.
    So I now guess that Spacecom runs a precise orbit reduction routine
    when some flag is set, maybe maximum positional error or like.
    If the flag is not set, they use a faster simplified routine.
    So we cannot easily judge if we see in elsets a real trend in, 
    say, inclination, or it's an artefact from algorithms used.
    Igor Lissov
    > > What is the physics (or is it mathematics?) behind the irregular jumps
    > > in plots (inclination vs. time) by some 0.005 degs for such objects as
    > > 27559, 27561, 27597-27601, 27605-27612 etc.?
    > >
    > Mathematics: For a LEO orbit this corresponds to +- 0.7 km, and this is
    > as I recall the approximate accuracy of TLEs.
    > Physics: Except for seemingly random jumps, there are secular inclination
    > changes, ie for the sun-sync orbits about -0.06 degrees/year.
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