Loading ...
Sorry, an error occurred while loading the content.

Rain attenuation

Expand Messages
  • Alan Sewards
    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
    Message 1 of 1 , Nov 2, 2004
    • 0 Attachment
      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

      Alan Sewards
      email: alan.sewards@...
      web site: http://asewards.free.fr
    Your message has been successfully submitted and would be delivered to recipients shortly.