EUMETCast switch from Eurobird-9 to Eurobird-9A

On 2009 February 24 the EUMETCast service was switched from Eurobird-9 (which was the old Hotbird-2) to Eurobird-9A (which was the old Hotbird-7A) unlike the previous switch in December 2008, this was between two satellites in the same orbital position and running on the same frequency.  To the users, it just appeared as a short break in service from 01:00 to about 01:02 UTC on 2009 February 24.  I happened to be watching the signal at the time, and on the dot of 01:00 the signal disappeared, to be replaced a few seconds later by a low-level signal on the same frequency, which also dropped for a few moments to be replaced by another signal which gradually ramped up in power.

The footprint of Eurobird-9A favours those in southern England and central Europe, so many stations saw an increase in signal strength, back to the levels they had been used to with the original Hotbird-6 satellite from 2003.  However for those in the north, a signal drop has been seen, coupled with a further decrease since the time of the changeover.

The graphs below, made some 18 hours after the changeover, more or less speak for themselves.

  • The SkyStar cards report SNR in dB, the DVBWorld/Dexatek boxes report strength in percent.
  • The PCI 2.3 card at Porthcawl seems to have gone into a "saturated" signal mode, with small variations in the stronger signal no longer being shown.
  • Only one PC of those shown here actually lost lock and needed manual recovery.

There is a separate plot of the four Edinburgh systems here.

You can see the current Europe data here, and the current Edinburgh data here.


The Edinburgh Systems

The Edinburgh systems show a snapshot some 32 hours after the changeover.  Although the initial drop was only a fraction of a dB in SNR and a couple of percent in signal quality, the signal has deteriorated since the changeover, and is now at a noticeably more marginal level.  This is rather disappointing, and may reduce the reliability of the EUMETCast system here in periods of rain, snow, ice-crystals or fog.


See also:


Copyright © David Taylor, Edinburgh   Last modified: 2015 Jan 18 at 09:32