... 2) In fact you can plot the value 1/ndot2 over epoch date for a well-behaved decay, and see that it approaches a straight line when the eccentricity get close to 0. 2013/9/7 Björn Gimle <bjorn.gimle@gmail.com> > 2) Yes and no. The test is fairly accurate, but only when it has reduced > its eccentricity to about .005 or below. This still corresponds to a > difference of about 130 km from perigee to apogee, so it spends more than > half its time with less than 1/3 the drag of perigee ! > ... > > 2) Would the calculation that you suggest combined with the orbital epoch > provide a good test to exclude a satellite? That is, if Epoch+0.05/ndot2 > yields a date before today's date, should it be safe to tag it as "probably > decayed" (for eccentricity<0.2 maybe)? And if the difference between that > calculated decay date and today's date is, let's say, greater than ten days > (a significantly larger time difference, in other words), is there any way > that it might not yet be decayed? I understand your point about higher > eccentricity orbits so might it be safer to use a test based on calculated > perigee? Maybe if the perigee is below 50km I can safely drop it from a > prediction list?? > -- ---------------------------------------- Björn Gimle, COSPAR 5919 59.2576 N, 18.6172 E, 23 m Phone: +46 (0)8 571 43 312 Mobile: +46 (0) 704 385 486 -------------- next part -------------- An HTML attachment was scrubbed... URL: http://mailman.satobs.org/mailman/private/seesat-l/attachments/20130907/48871387/attachment.html _______________________________________________ Seesat-l mailing list http://mailman.satobs.org/mailman/listinfo/seesat-l
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