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. ----------------------------------------------------------------- To unsubscribe from SeeSat-L, send a message with 'unsubscribe' in the SUBJECT to SeeSat-L-request@satobs.org List archived at http://www.satobs.org/seesat/seesatindex.html
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