[Skimmertalk] Bad Skimmer Spots
K1TTT
K1TTT at ARRL.NET
Fri Feb 4 14:21:15 PST 2011
PLEASE! Do not remove ANY data from the raw stream that we can get for arc6,
I would much rather have the filter flexibility close to the user end.
David Robbins K1TTT
e-mail: mailto:k1ttt at arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: Pete Smith [mailto:n4zr at contesting.com]
> Sent: Friday, February 04, 2011 21:18
> To: Igor Sokolov
> Cc: Skimmertalk at contesting.com; K1TTT
> Subject: Re: [Skimmertalk] Bad Skimmer Spots
>
>
> I thought everyone might enjoy seeing a little slice of
> actual RBN data,
> from a small part of the first minute of February 3 (Z time):
>
> callsign de_pfx de_cont freq band dx
> dx_pfx dx_cont mode db date
> DK9IP DL EU 3523.8 80m E77AW E7
> EU CQ 15 2/3/2011 0:00
> G4HSO G EU 3523.9 80m E77AW E7
> EU CQ 28 2/3/2011 0:00
> DL2CC DL EU 3523.8 80m E77AW E7
> EU CQ 30 2/3/2011 0:00
> S50ARX S5 EU 3523.8 80m E77AW E7
> EU CQ 34 2/3/2011 0:00
> SV8RV SV EU 3523.9 80m E77AW E7
> EU CQ 22 2/3/2011 0:00
> ES5PC ES EU 3523.8 80m E77AW E7
> EU CQ 26 2/3/2011 0:00
> ES5PC ES EU 7014.2 40m OK2KJU OK
> EU CQ 20 2/3/2011 0:00
> WZ7I K NA 7014.2 40m OK2KJU OK EU
> CQ 16 2/3/2011 0:00
> SV8RV SV EU 7014.2 40m OK2KJU OK
> EU CQ 32 2/3/2011 0:00
> DL0LBS DL EU 3523.8 80m E77AW E7
> EU CQ 22 2/3/2011 0:00
> OL5Q OK EU 3523.8 80m E77AW E7 EU
> CQ 22 2/3/2011 0:00
> HB9SOF HB EU 3523.9 80m E77AW E7
> EU CQ 11 2/3/2011 0:00
> K8ND K NA 7011 40m LZ2VU LZ EU
> CQ 19 2/3/2011 0:00
> UA9CLB UA9 AS 3523.8 80m E77AW E7
> EU CQ 9 2/3/2011 0:00
> WA7LNW K NA 7029 40m K7DCG K
> NA CQ 29 2/3/2011 0:00
> NC7J K NA 7029 40m K7DCG K NA
> CQ 23 2/3/2011 0:00
> N7TR K NA 7029 40m K7DCG K NA
> CQ 39 2/3/2011 0:00
> K3LR K NA 7029.1 40m K7DCG K NA
> CQ 17 2/3/2011 0:00
> VA7DZ VE NA 7029.1 40m K7DCG K
> NA CQ 20 2/3/2011 0:00
> TF3Y TF EU 3523.8 80m E77AW E7 EU
> CQ 12 2/3/2011 0:00
>
> As you can see, a legitimate station can easily get as many
> as ten spots
> from different Skimmers, in a single minute, even on a mid-week
> non-contest day. What we really need is both de-duping (same
> frequency,
> same callsign, same minute) and de-junking (10 spots on a
> frequency, 9
> calls spotted the same, same minute, one different). We
> think the RBN
> can develop means to take care of the second. N1MM Logger
> and CC User
> are already taking care of the first.
>
> CC user is a neat piece of middleware for those whose clients haven't
> yet caught up. I *believe*, but can't swear, that its
> de-duping works
> with all cluster node software, not just VE7CC's. Lee, can
> you confirm
> this?
>
> 73, Pete N4ZR
>
> The World Contest Station Database, updated daily at
> www.conteststations.com
> The Reverse Beacon Network at http://reversebeacon.net, blog
> at reversebeacon.blogspot.com,
> spots at telnet.reversebeacon.net, port 7000
>
>
>
> On 2/4/2011 12:36 PM, Igor Sokolov wrote:
> > David, I am not aquainted with arc-6 but what you describe
> is pretty
> > close to what I need. I need to be able to choose either cluster
> > spots or skimmer spots or both. Preferably with separate
> filtering for
> > each of the two. For skimmer spots I need additional
> filtering based
> > on the number of skimmers generating spots for the same
> call (choose
> > 2, 3 or even 4) plus filtering based on master.dta. Having
> been able
> > to choose all these filters in any combination would be ideal.
> > CC client has a very good user interface which allow user not to
> > remember all those filtering commands required by cluster software.
> > Adding filtering described above to CC software using the same easy
> > user interface would be a great advantage.
> >
> > 73, Igor UA9CDC
> > ----- Original Message ----- From: "K1TTT" <K1TTT at ARRL.NET>
> > To: <n4zr at contesting.com>; "'Igor Sokolov'" <ua9cdc at gmail.com>
> > Cc: <Skimmertalk at contesting.com>
> > Sent: Friday, February 04, 2011 7:11 PM
> > Subject: RE: [Skimmertalk] Bad Skimmer Spots
> >
> >
> >> That is why arc-6 is passing all the rbn spots on to the
> client, so
> >> duping
> >> and filtering can be done by the user. You might also
> want to check out
> >> some of the new filters, in the latest beta update there
> is a number of
> >> times spotted filter, so you can limit the rbn spots you
> see to ones
> >> that
> >> have been spotted 2 or more times, and there is also a master.dta
> >> filter to
> >> only see spots in the supercheck database... Those filters can be
> >> combined
> >> in statements like:
> >>
> >> not skimmer or (skimmer and unique > 2) or (skimmer and master)
> >>
> >> Which would give you all non-skimmer spots, plus skimmer
> spots that are
> >> spotted more than twice on the same band within 10
> minutes, plus skimmer
> >> spots that are in the master.dta file regardless of how many times
> >> they are
> >> spotted.
> >>
> >>
> >> David Robbins K1TTT
> >> e-mail: mailto:k1ttt at arrl.net
> >> web: http://www.k1ttt.net
> >> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> >>
> >>
> >>> -----Original Message-----
> >>> From: Pete Smith [mailto:n4zr at contesting.com]
> >>> Sent: Friday, February 04, 2011 13:38
> >>> To: Igor Sokolov
> >>> Cc: Skimmertalk at contesting.com
> >>> Subject: Re: [Skimmertalk] Bad Skimmer Spots
> >>>
> >>>
> >>> There is a third possibility, but the problem is a little
> >>> trickier than
> >>> I had thought. Here's an excerpt I just sent to someone on
> >>> another list:
> >>>
> >>> "As for the theoretical error rate, let's take an example.
> >>> Say you have
> >>> N6NC CQing for an hour and being heard by 10 RBN Skimmers.
> >>> Each Skimmer
> >>> will spot you correctly 5-6 times (every 10-12 minutes).
> But if some
> >>> local event - transmitter splatter, QRN, QRM (especially
> things like
> >>> clicks from a loud adjacent station) causes a mis-spot, then
> >>> whichever
> >>> Skimmer that mis-spotted you will immediately send out a bad spot.
> >>>
> >>> Say just one of the Skimmers listening to you sends one bad
> >>> spot of you
> >>> in that hour. That's 1 bad spot. Meanwhile, the good
> spots are being
> >>> filtered out as dupes by client software, so that clients are only
> >>> receiving 5-6 good spots of you. Holy cow, that's a 16-20 percent
> >>> apparent error rate.
> >>>
> >>> It's the aggregation, which is why the RBN has to come up with a
> >>> solution. This is a fairly tricky problem, because the
> system has a
> >>> built-in preference for new spots, whether good or bad. The
> >>> bad spots
> >>> can come at any time when you are CQing. Meanwhile, the good
> >>> spots will
> >>> tend to cluster, because most people who spotted you
> >>> correctly will have
> >>> done so within a few seconds of your first CQ, and then at
> >>> 10-12 minute
> >>> intervals thereafter. I don't know just how this one
> will be solved,
> >>> but I think it can be. The devil, as usual...
> >>>
> >>> 73, Pete N4ZR
> >>>
> >>> The World Contest Station Database, updated daily at
> >>> www.conteststations.com
> >>> The Reverse Beacon Network at http://reversebeacon.net, blog
> >>> at reversebeacon.blogspot.com,
> >>> spots at telnet.reversebeacon.net, port 7000
> >>>
> >>>
> >>>
> >>> On 2/3/2011 11:38 PM, Igor Sokolov wrote:
> >>> > Lee, I think it would be excellent if VE7CC client software
> >>> could have
> >>> > filtering and validation facilities. There were so many
> >>> broken spots during
> >>> > CQWW 160 that filled the entire band map and their
> >>> percentage was reaching
> >>> > 80% on the last night of the contest.
> >>> > I see two methods of validating spots:
> >>> > 1) pass the spot if the call has been mentioned by 2 or 3
> >>> other skimmers
> >>> > 2) Pass the spot if it is in the master. dat file.
> >>> > Combination of these two would probably cut the number of
> >>> broken spots to
> >>> > acceptable figures.
> >>> > I think telnet client software is the best place for
> >>> filtering (better then
> >>> > filter in the logger or at the skimmer)
> >>> >
> >>> > 73, Igor UA9CDC
> >>> > ----- Original Message -----
> >>> > From: "Lee Sawkins"<ve7cc at shaw.ca>
> >>> > To:<Skimmertalk at contesting.com>
> >>> > Sent: Friday, February 04, 2011 3:12 AM
> >>> > Subject: [Skimmertalk] Bad Skimmer Spots
> >>> >
> >>> >
> >>> >> Here is a small subset of bad skimmer spots. I am looking
> >>> at a full feed
> >>> >> from the RBN.
> >>> >>
> >>> >> These are only spots for USA calls that have not been
> >>> issued. Many times
> >>> >> the first letter of a call is missing. Many of these are
> >>> actually Italian
> >>> >> calls with the "I" missing.
> >>> >>
> >>> >> http://www.bcdxc.org/ve7cc/notissue.txt
> >>> >>
> >>> >> I will update the list from time to time.
> >>> >>
> >>> >> CC Clusters drop these bad calls.
> >>> >>
> >>> >> There are many other non USA calls that are wrong which
> >>> also have the
> >>> >> first
> >>> >> letter missing. These are harder to find.
> >>> >>
> >>> >> Other bad calls occur when the last letter is missing or
> >>> truncated or is
> >>> >> added
> >>> >> +in error.
> >>> >>
> >>> >> "E" and "T" seem to be the most often added bad letters.
> >>> >>
> >>> >> Lee
> >>> >> _______________________________________________
> >>> >> Skimmertalk mailing list
> >>> >> Skimmertalk at contesting.com
> >>> >> http://dayton.contesting.com/mailman/listinfo/skimmertalk
> >>> > _______________________________________________
> >>> > Skimmertalk mailing list
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> >>> >
> >>> >
> >>> _______________________________________________
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> >>>
> >>
> >>
> >
> >
> >
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