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Re: [CQ-Contest] Implementing a Dynamic error free RBN-Skimmer network

To: Ron Notarius W3WN <wn3vaw@verizon.net>
Subject: Re: [CQ-Contest] Implementing a Dynamic error free RBN-Skimmer network
From: "Martin , LU5DX" <lu5dx@lucg.com.ar>
Date: Wed, 17 Jul 2013 22:03:25 -0300
List-post: <cq-contest@contesting.com">mailto:cq-contest@contesting.com>
Not saying that preventing MS/M2/MM from alternating CQ is a bad thing at
all.
I fully agree with the rule.
I was just saying that no stations are supposed to dual CQ on the same
band, eliminating the need for such filter in the logic proposed by Jose
(of course not saying it's the same case as I/Q image problem), as the
pattern is totally different.

Vy 73.

Martin, LU5DX





On Wed, Jul 17, 2013 at 6:59 PM, Ron Notarius W3WN <wn3vaw@verizon.net>wrote:

> And this is bad because... ?
>
> -----Original Message-----
> From: CQ-Contest [mailto:cq-contest-bounces@contesting.com] On Behalf Of
> Martin , LU5DX
> Sent: Wednesday, July 17, 2013 5:32 PM
> To: CQ-Contest
> Subject: Re: [CQ-Contest] Implementing a Dynamic error free RBN-Skimmer
> network
>
> I guess no stations can call CQ on alternate frequencies on the same band
> now (MS/M2/MM)...
>
> Vy 73.
>
> Martin, LU5DX
>
>
> On Wed, Jul 17, 2013 at 3:53 PM, Igor Sokolov <ua9cdc@gmail.com> wrote:
>
> > Very well done Jose. Thank you much. I have enjoyed reading it.
> >
> > Couple of thoughts came to my mind.
> > There are instances where one station can be heard on several
> frequencies.
> > 1) Stations with parasitic AM modulation can have 3 signals spaced aprox.
> > 1.5 kHz
> > 2) Second and third harmonic signals.
> > 3) Multy/ Multy stations.
> >
> > How does your algorithm treats these cases?
> >
> > 73, Igor UA9CDC
> >
> > ----- Original Message ----- From: "José Nunes CT1BOH" <ct1boh@gmail.com
> >
> > To: <cq-contest@contesting.com>
> > Sent: Tuesday, July 16, 2013 4:23 AM
> > Subject: [CQ-Contest] Implementing a Dynamic error free RBN-Skimmer
> network
> >
> >
> > The purpose of this post is to present a way to implement a dynamic error
> > free Skimmer-RBN/Packet network that automatically:
> >
> > 1. Flags and eliminates “Busted Spots” from the network
> > 2. Flags  and eliminates “wrong frequency” spots from the network
> > 3. Prevents inaccurate Skimmer-Spotters from feeding incorrect spots to
> the
> > network
> > 4. Eventually allow the Skimmer-RBN users to customize reception of spots
> > according to the quality flag and several parameters of the algorithm
> >
> > In my various CQWW CW operations since 1989
> >
> http://www.qsl.net/ct1boh/**operations.htm<
> http://www.qsl.net/ct1boh/operati
> ons.htm>I’ve only enjoyed
> > Skimmer-RBN/Packet networks from the pile-up end side as PY0F, P40E,
> CR3E,
> > etc.
> > Skimmer-RBN and packet network has been a blessing for the DX operator as
> a
> > constant pile-up generator and a reason for the never ending increase in
> > total QSO number throughout the years.
> >
> > Recently, building the idea of operating Assisted on CW from a DX
> location
> > for the first time, I begun to study how to correctly use
> > Skimmer-RBN/Packet networks. Operating Assisted in minor Contests from
> > home, I discovered several problems that made the use of callsign and
> > frequency information from a RBN feed band map not 100% reliable:
> >
> > - Busted spots
> > - Non-existent spots on a particular frequency
> > - Small frequency shifting spots and
> > - “Unstable” band map with callsigns alternating, popping-in and
> > popping-out
> >
> > Wanting to use Assistance and not being able to completely trust the
> > information is a strange concept to me. If I use Assistance I would
> expect
> > not to waste time in my mind processing if the call in the band map is
> good
> > or bad.
> >
> > Solving the problems requires a system that is able to automatically
> assess
> > the spot before send it to the network and “learns” from itself. The
> > solution is a dynamic error free RBN-Skimmer algorithm.
> >
> > Studding RBN data that can be downloaded here
> >
> http://www.reversebeacon.net/**raw_data/<
> http://www.reversebeacon.net/raw_da
> ta/>I came to a solution. The algorithm
> > I propose has a simplicity beauty and works extraordinary well. For every
> > new spot that is provided to the Reverse Beacon Network by a Skimmer
> > Spotter or by a packet network by a human, the system will automatically
> > generate the following “Quality Tag” for each spot:
> >
> > Good Spot
> > Good Call, New Frequency Spot?
> > Busted Spot
> > ? Spot
> >
> > In short, the algorithm can be described as follows:
> >
> > Any new spot will be tagged as a “Good Spot” if looking back 25 minutes
> > there are two more Spots with the same call as the new spot, in the
> > approximate same frequency (+/- 0.3 Khz)
> >
> > Any new spot will be tagged as a “Good Call, New Frequency Spot?” if
> > looking back 25 minutes there is a Spot that was already tagged as “Good
> > Spot”, with the same call as the new spot, but the new spot is in an
> > adjacent frequency (less or equal than -0.4 Khz and greater or equal than
> > +0.4 Khz)
> >
> > Any new spot will be tagged as “Busted Spot” if looking back 25 minutes
> > there are at least three already tagged “Good Spot” with a similar call,
> in
> > the approximate same frequency of the new spot (+/- 0.1 Khz). The similar
> > call is a call that can be transformed into the new spot call by
> character
> > insertion, deletion or substitution.
> >
> > Any Spot that is not a “Good Spot”, a “Good Call, New Frequency Spot?” or
> a
> > “Busted Spot” is an undetermined spot “?Spot”.
> >
> > Let’s have a closer look at it, with examples from RBN spots from CQWW CW
> > 2012:
> >
> > “Good call” quality flag
> >
> > #1       call1    freq1   time1   #Spotter      Quality tag
> > 711     CR3E   7045    4           #G4HYG       ?Spot
> > 860     CR3E   7045    5           #WB8BIL      ?Spot
> > 918     CR3E   7045    5           #WB2LSI      Good Spot
> > 3077   CR3E   7045    20         #G4HYG       Good Spot
> > 3254   CR3E   7045    21         #S52AW       Good Spot
> > 3336   CR3E   7045    22         #KB9AMG    Good Spot
> > 3892   CR3E   7045    25         #DK9IP         Good Spot
> > …
> > CR3E started the contest (CQWW CW 2012) on 7045. The first two spots get
> > the quality flag “?Spot”, but by the third spot of WB2LSI skimmer CR3E is
> > flagged as a “good call” and all subsequent spots on 7045 will get the
> > “Good Spot” quality flag.
> > After a lot of testing I can say the system should operate with a
> bandwidth
> > filter of +/- 0.3 KHz. All spots that do not fall within this +/- 0.3 KHz
> > filter will not get the “Good Spot” quality tag.
> >
> >
> > “Good Call, New Frequency Spot?”
> >
> > #1          call1    freq1      time1   #Spotter      Quality tag
> > …
> > 33721   CR3E   7045       220       #F5MUX       Good Spot
> > 34154   CR3E   7041.3    223       #KA9SWE     Good Call, new freq?
> > 34460   CR3E   7045       225      #RU9CZD      Good Spot
> > …
> > 40711   CR3E   7044.9    261       #KQ8M         Good Spot
> > 40740   CR3E   7041.3    261       #KA9SWE    Good Call, new freq?
> > 41213   CR3E   7045.1    264       #K3LR          Good Spot
> > …
> > CR3E continues to be on 7045. All of a sudden #KA9SWE skimmer spots CR3E
> on
> > 7041.3. The systems detects a frequency difference and flags it as a
> “Good
> > call, new frequency?”.  Is it really a QSY to a new frequency by CR3E? If
> > yes, then, shortly after two more spots the system will change the flag
> to
> > “Good spot”. It is not the case in this example because skimmer #RU9CZD
> > confirms there was no QSY. Later on we see that #KA9SWE sends another
> spot
> > on 7041.3.Obviously #KA9SWE skimmer needs frequency calibration.
> > After a lot of testing I can say the system should operate with a
> bandwidth
> > filter of greater than +/- 0.3 Khz. All spots that do not fall within
> this
> > +/- 0.3 KHz filter will not get the “Good Spot” quality tag, and this
> > should be the accuracy threshold.
> >
> >
> > “Busted Spot”
> >
> > #1          call1       freq1     time1   #Spotter      Quality tag
> > 31159   CR3E      7045      204       #S52AW      Good Call
> > 31172   KR3E      7045      204       #K9QC          Busted
> > 31205   CR3E      7045      205       #G4HYG       Good Call
> > …
> > CR3E continues to be on 7045. All of a sudden #K9QC skimmer sends a KR3E
> > spot. The system detects that KR3E is a similar call of CR3E on the same
> > frequency of a Good Spot and it will flag this spot as a Busted spot. The
> > system uses Levenshtein distance to calculate a similar call (
> >
> http://en.wikipedia.org/wiki/**Levenshtein_distance<
> http://en.wikipedia.org/
> wiki/Levenshtein_distance>).
> >  Depending on the
> > length of the callsign it will look for calls that are x-off letters
> away.
> > After a lot of testing I can say the system should operate with a
> bandwidth
> > filter of +/- 0.1 Khz. A Busted Spot comes from a good spot, and usually
> > from Skimmer that has already spotted the call, therefore a threshold of
> > 0.1 is what works best.
> >
> >
> > “?Spot”
> >
> > All “?Spot” are spots that cannot be determined as “Good Spot” or as
> “Good
> > Call, New Frequency Spot?” or as “Busted Spot”.  Some are good spots –
> The
> > first and the second spot on a new frequency when a run starts. But the
> > majority is “spots” send by skimmers, of stations calling RUN stations.
> > These spots should never be sent out to the network by skimmer. They are
> > false positive running stations.
> >
> >
> > How does this proposed system works?
> > I can say it works extraordinary well!
> >
> > I tested all 40 meter spots from CQWW CW 2012 – almost a million sots:
> >
> > Quality flag                               Spots        % of spots
> > ?                                            46.593              4.69%
> > Busted                                   20.734               2.09%
> > Good Call                             855.227              86.08%
> > Good Call, new freq?               70.994               7.15%
> > Grand Total                          993.548            100.00%
> >
> > After running my algorithm I also went back to validate both “? Spots”
> and
> > “Good call, new freq?” spots. If I have the following spots:
> > 711     CR3E   7045    4           #G4HYG       ?Spot
> > 860     CR3E   7045    5           #WB8BIL      ?Spot
> > 918     CR3E   7045    5           #WB2LSI      Good Spot
> > It is easy to determine after running the algorithm that spot #711 and
> > spot#918 are “Good Spots” from spot 918. This cannot be done with a real
> > time system, because once a quality tag is given to a spot it is given.
> >
> > Of the 46.593 spots with “?Spot” quality flag:
> >     20768 are good calls (these are all the first and second spot of a
> run
> > that just started)
> >     25825 spots are indeed “? Spots” (mostly stations calling on
> pile-ups)
> >
> > Of the 70.994 spots with “Good Call, New Freq?” quality flag:
> >     24.502 are good call (these are all the first and second spots of a
> > run that just started in a new frequency)
> >     46.492 spots are indeed “Good Call” that are sent to the network with
> > a wrong frequency by an uncalibrated skimmer.
> >
> > My algorithm also allows the RBN to detect uncalibrated skimmer spotters.
> >
> > Looking at the list of skimmers it is easy to build a list based on the %
> > of “Good call, New freq?” quality flag. Let’s take a look at the top ten
> > Skimmer spotters according to spots sent to the RBN:
> >
> > Skimmer     Spots          % of “Good Call, New Freq?”
> > #K3MM     45.726         3.1%
> > #GW8IZR  29.984         8.7%
> > #S52AW    29.214        5.2%
> > #DL8LAS   26.906         3.7%
> > #DR1A      25.831         3.1%
> > #RU9CZD 24.301          6.4%
> > #HA6PX     23.317      38.6%
> > #OL5Q      23.006         4.4%
> > #W3LPL   21.889          2.0%
> > #KQ8M    21.833          7.1%
> >
> > We can see that a calibrated skimmer should not have more than 3% of
> “Good
> > Call, New frequency?” spots, because that is the dynamic of people
> changing
> > frequency in the contest. Numbers greater than that show uncalibrated
> > skimmers, such is the case of #GW8IZR, #HA6PX, or #KQ8M.
> >
> >
> > To finalize several considerations:
> >
> > 1 RBN (Reverse Beacon Network) is a fantastic instrument for contesters
> and
> > DXers.
> > 2 We have the instruments to turn the current RBN network into a dynamic
> > error free system
> > 3 The system should allow the user to decide to filter out “Busted”
> spots,
> > “Good call, New Freq?” spots and “? Spots”. By giving a quality flag it
> > would be up to the user to use the quality flags to filter out spots
> > 4 The system should warn uncalibrated skimmers
> >
> > If you want to play with the data and with the algorithm you can:
> > The algorithm and several graphs that explain how well the system works
> is
> > available to download here
> > http://www.qsl.net/c/ct1boh//**dl/ <http://www.qsl.net/c/ct1boh//dl/>
> > Please note that the excel file is ~90MB
> >
> > In sheet 1 there are 993.548 spots from CQWW CW 2012 on 40 meters
> > In sheet 2 there is the results of the algorithm. This would be the
> output
> > of the system with real time adding a quality flag to each spot (if you
> do
> > Alt-Q you will activate the macro. it takes 1892 seconds to flag all
> > 993.548 spots on my PC. Or on average 0.0019 seconds to flaf every
> incoming
> > spot.
> > In sheet 3 there is a pivot table to manipulate data from sheet 2
> > In sheet 4 there is a list and graph that show the performance of
> skimmers
> > as far as frequency calibration is concerned
> > In sheet 5 there is a list and a graph of calls and the % of Busted of
> each
> > call according to number of spots
> > In sheet 6 there is the algorithm code (please note that I’m not a
> > programmer. I just learned VBA to do this)
> >
> >
> > --
> > José Nunes
> > CONTEST CT1BOH - http://www.qsl.net/ct1boh
> > ______________________________**_________________
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> > CQ-Contest@contesting.com
> >
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