Observation 22534 [dev network]

Hey all,

In this waterfall:

it seems to me that the AFSK1200 bars are slightly shifted in frequency
around doppler center.
Could there be another quirk in TLEs like for NOAA sats which affects doppler
[or arrival time], or is it an effect of a too early scheduling?
The shift is coherent with estimated position a bit early with
satellite actual position. Could the mean motion have been again
slightly over estimated?

It can also be seen in observation from Dimitrios:


This is similar to NOAA sats but has a different cause. For NO-84, NO-83 and AO-85(FOX-1A) celestrak doesn’t distribute TLE, as far as I know it is a legal issue.

There are other sources for these satellites like the amsat list of TLE. For now, our only source for automatically update TLE is celestrak. So, for these three satellites, a manual update is needed which is usually done every 1 to 2 weeks.

Until getting TLE from multiple sources is implemented (and this is also an invitation to whoever wants to contribute), if you see a significant drift feel free to ping me (pm here or in irc/matrix(riot)) and I’ll update the TLE. :wink:

1 Like