On Thu, 21 Apr 2011, Tom Yoksas wrote:
Hi Gilbert, et. al.,
A quick update on DVB-S2 testing here at the UPC...
We received and installed our Novra S300 receivers on this past Tuesday,
April 19. We configured one of the receivers for DVB-S use and the other
for DVB-S2 use. Two of the three NOAAPort reception machines we operate
here in Boulder remain ingesting the DVB-S datastream and powering
(along with other community machines) the IDD. The third system is
ingesting the DVB-S2 datastream and feeding all of its data to a UPC
test machine on which all data are being decoded by McIDAS-XCD decoders.
Our experience so far is that the quality of the data being delivered
by the DVB-S2 broadcast is measurably worse than that delivered by the
DVB-S datastream meaning that we are seeing lots of Gap messages and
missing lots of products.
rtstats comparisons of the two datastreams can be made by viewing the
'volume' and/or 'products' links for machines ingesting each type of
broadcast:
DVB-S
http://www.unidata.ucar.edu/cgi-bin/rtstats/siteindex?jackie.unidata.ucar.edu
DVB-S2
http://www.unidata.ucar.edu/cgi-bin/rtstats/siteindex?burns.unidata.ucar.edu
The reception quality as indicated by Novra 'cmcs' output on our DVB-S2
machine is good:
CMCS 192.168.1.20> show satellite
Satellite Interface Settings:
Receiver MAC Address: xx-xx-xx-xx-xx-xx
Receiver Mode: DVBS2
Frequency: 1142.0 MHz
Symbol Rate: 15.120 Msps (Auto)
ModCod: 2/3 8PSK
Gold code: 0
Input Stream Filter: On
Input Stream ID: 13
Signal Lock: On
Data Lock: On
Uncorrectable Rate: 0/Second
Packet Error Rate: 0.0000e+00
Carrier to Noise C/N: 15.3dB
Signal Strength: -46 dBm
CMCS 192.168.1.20>
This coupled with the large number of Gap messages we are seeing suggests
that there are (still) problems with DVB-S2 uplink system. This agrees
with comments made in a previous announcement by NOAA:
Like everyone else testing DVB-S2, we are eager to see a resolution of
this problem!
Yessir. My stats page is now back up:
http://noaaport.admin.niu.edu:/8025
If you want a look and see what my stats are with the new broadcast. I
just installed the new version of this software to support it, but data
will be populating through this afternoon. It's still useful now,
obviously.
*******************************************************************************
Gilbert Sebenste ********
(My opinions only!) ******
Staff Meteorologist, Northern Illinois University ****
E-mail: sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://weather.admin.niu.edu **
*******************************************************************************
