- The other day we had a long period of relatively steady rain. During the
evening we were trying to watch a channel on satellite TV but it kept
breaking up so we abandoned the attempt. I took a look at my MSG-1 system
and saw that there were missing segments. I checked with Setup4PC and it
showed the signal quality at 40-50% with SNR varying between 6.3 and 8.5 dB.
My weather station showed the rainfall rate as being 8-9 mm/hr. A few
minutes later the rain increased, showing as 10 mm/hr, and the quality
dropped to 21 and then 14%, with SNR 3.3 and 2.5 dB respectively. The BER
under these conditions was very poor - around 10**-2, so it was not
surprising that I was losing segments. In fact, I did not lose very many - a
total of 120 segments during 5 cycles, which is a tribute to all the coding
present! I don't have a lot of faith in the rainfall rate numbers, as the
system uses a tipping bucket sensor, the tips being counted electronically.
This has built in delays and integration, so it is likely that the actual
rainfall rates during the segments loss was more than indicated, but I
thought that the numbers might be of interest to others. The rainfall total
during the day, incidentally, was 75 mm.
Best regards - Alan
web site: http://asewards.free.fr