Equipment for receiving MSG-1
Alan Sewards <alan.sewards@...>
While John is busy collating the inputs from those who have participated in
the MSG-1 dissemination trials, I thought it might be of interest to
question some of the basic assumptions. The main one of these is that one
needs to have two computers, one for the reception function and one for the
decoding. Because I only had one, I had to make do with it for all
functions, and in doing so I expected I would lose some of the data.
However, as time has gone on, I have begun to realise that any data that
might have been lost due to possible overload of the single computer is
insignificant compared with data lost from other sources associated with the
dissemination trials. In fact, I did a test overnight where I stopped the
MSG DM and then restarted it at 0500UTC, so it had about 12 hours of
captured data to process, which is does in what I call 'catch-up' mode, that
is running flat out with the CPU utilization running around 80-100% on a
continuing basis. It took about two hours to process all the stored data
and, as far as I could tell by a visual inspection of the thumbnails, there
were no missing segments in either the period of stored data or in data
captured during the catch-up processing. This leads me to suspect that a
single computer is all that is needed for MSG reception, provided of course
that it has sufficient power. I should note here that I only collect seven
of the 12 HRIT channels, all the LRIT and FSD, so I do not have a full load.
I may try an experiment of collecting the full set and see if that makes any
difference. My computer is nothing special, 1800 Athlon, with 512 MB.
Because I have had great difficulty in getting two computers running
Windows XP to network properly, I am seriously considering departing from
the two-computer concept and sticking with a single one for MSG, and I feel
pretty confident that it will work. Anyone else had similar thoughts? Should
we do some serious tests to find out if two computers are really necessary?
Best regards - Alan
web site: http://asewards.free.fr