[Skimmertalk] Skimmer Callsign Validation

[Pete Smith]

One of the early criticisms of the first version of CW Skimmer was that it 
posted too many busted calls.  In response to that criticism, Alex has 
introduced, in version 1.2, a user-selectable 4-level validation 
scheme,  ranging from "minimal" to "paranoid."  Each level tests the 
callsign as copied against progressively tougher criteria, both in terms of 
the number of times it must be copied and in whether it matches against 
patterns derived from an analysis of 11 years of cluster spots.  The 
"paranoid" level does not post a callsign unless it matches one in a 
master.dta file, known among contesters as "Super Check Partial."

During the recent WPX CW contest, DL6MHW recorded 17 minutes on 40 meter 
CW.  Using his recording, I ran CW Skimmer in each of the four validation 
modes, told it only to spot stations that were CQ-ing, and collected the 
spots.  WG4M, a Microsoft Access maven, analyzed the lists of spots and 
arranged them in a table that shows each unique callsign copied by Skimmer 
and how it fared through the four validation modes.  You can clearly see 
how Skimmer now becomes progressively more "skeptical" when the more 
stringent validation modes are used.

There is a Microsoft Excel file at 
www.pvrc.org/~n4zr/Summary_of_All_Calls_6-27-08.xls that summarizes the 
results.  Callsigns color-coded red in the left-most column were not found 
in QRZ.com but were accepted by one or more of the validation levels above 
minimal - at least some may be good, because QRZ is not perfectly timely or 
inclusive.  Similarly, call-signs colored yellow in that column were found 
in QRZ but were not validated by any level above minimal (I call them false 
negatives).

The results aren't perfect - but I think they clearly show that Skimmer is 
now at least comparable in accuracy to the average human op who posts spots 
on the DX cluster network.  Not bad!  If you want to see for yourself, 
click on the URL above - if you enter it manually, be sure you put 
underscore characters everywhere there appears to be a space.  Comments 
welcome!


73, Pete N4ZR