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Re: LF: New version OPERA >> ''Opera Dynamic'' <<

To: [email protected], [email protected]
Subject: Re: LF: New version OPERA >> ''Opera Dynamic'' <<
From: "Mike Dennison" <[email protected]>
Date: Thu, 08 Jan 2015 10:54:35 -0000
In-reply-to: <[email protected]>
References: <[email protected]>, <[email protected]>, <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
Having taken a long look at Opera 1.5.5, it seems to have good and 
band points, but is useful if used with great caution.

On the plus side, it appears to have some 3dB more sensitivity than 
previous versions of Opera. This is not better than DF6NM's OPDS 
program, but that is more complex to set up.

On the minus side is the number of believable false decodes which I 
think are being underestimated by the program's advocates. For 
instance, on day one one third of the times that my transmissions 
were reported I was off the air. On day two I transmitted once but 
was reported on two occasions. However, all of these false decodes 
were one-offs, in other words only one station reported me at that 
time, whereas several reported the genuine transmissions.

So, v1.5.5 looks very useful but any decodes that are reported by 
just one station has a high likelihood (but not certainty) of being 
false. For this reason, I would not advise using this version without 
having a web connection, or at least cross-checking later against the 
web archive.

Mike, G3XDV
==========

> Graham, thanks for the useful info. I have sent you a direct email
> with some constructive suggestions. 
> 
> One snag with false decodes of this type is that you don't know they
> are false unless the sender denies he was sending (or propagation is
> impossible) at that time, so there will be statistically far fewer
> reports of false decodes than there are in reality. I transmitted four
> times in the last 24 hours and there were two additional decodes
> falsely carryng my callsign in the same period. That's two out of a
> total of six, ie 33%.
> 
> regards
> Mike
> =====
> 
> > Some points Mike
> > 
> > 200%F  is  a  bodge to get the  text  beacon via   the  server , not
> > showing  in my  latest  spot listing ?
> > 
> >  JA8SCD de SWL-JA8SCD/1 (): Op32 0 mi -41 dB in Tokyo with 0w +
> > 16:29    136 JA8SCD de JA8SCD/1 Op32 Deep Search 0 mi -41 dB in
> > Tokyo with 0w +
> > 
> > 4 Min processing  delay  showing  in these  detection's
> > 
> > 16:15    136 LA3EQ de G4WGT Op32 Deep Search 468 mi -43 dB in
> > Chorley, IO83qo, with 0.2w + Marconi-T 16:11    136 LA3EQ de G8HUH
> > Op32 605 mi -34 dB F:15% in Somerset with 0.2w + Marconi-T
> > 
> > 17:23    136 LA3EQ de GW0EZY Op32 Deep Search 541 mi -42 dB in
> > Welshpool IO82ho with 0.2w + Marconi-T 17:23    136 LA3EQ de 2E0ILY
> > Op32 Deep Search 505 mi -42 dB in Shropshire IO82qv with 0.2w +
> > Marconi-T 17:19    136 LA3EQ de G8HUH Op32 605 mi -33 dB F:1% in
> > Somerset with 0.2w + Marconi-T
> > 
> > 
> > >> Nothing  can be  100% ,   Dynamic   detections ,  will  show   1
> > >> minuet after  conventional OP8   and   4  minuets   after  a
> > >> conventional  OP32  decode , this  is due  to  data  processing
> > >> time and  is a  fixed  off  set  , Time can be  used  as  a
> > >> reality
> > >>  check
> > 
> > 
> > There  are now  two  entirely  different  systems  packaged  in the
> > one application ,  the  original Opera  data  mode , which is 
> > capable  of presenting  the  fade pattern  and  the  s/n ,  the 
> > other
> >  relies  on  call matching  and  presents  s/n only  , hence  the 
> > 'odd' 200%F  , the  dynamic search has been trailed  on  normal 
> > 'ham' kit and  provides an extension to the  existing  system .
> > 
> > Before  any  variations  are  attempted ,  off  air  stats  are
> > needed , there  was  close  to  100  instances  of  V155  in use 
> > since  its launch ,  with  only  1 error  that  would be   1% .
> > Occurrences  will
> >  be statistically  related to  user  numbers
> > 
> > Where  it  is  unfortunate   'real'  calls  are  produced  , the 
> > time delay  presents a  simple , at a glance spot-check , the
> > integrity of the original  system has not  been  compromised, at the
> >  moment  the list has a  8 day  life , this  could be  reduced , but
> >  with the  7 day operating cycle ,  8  provides overlap
> > 
> > 73-G,
> > 
> > 
> > 
> > --------------------------------------------------
> > From: "Mike Dennison" <[email protected]>
> > Sent: Wednesday, January 07, 2015 3:37 PM
> > To: <[email protected]>
> > Subject: Re: LF: New version  OPERA  >>  ''Opera Dynamic'' <<
> > 
> > > Sorry, Graham, but you are wrong. Last night's results did not
> > > "give a good working compromise between real and false
> > > detections." There were several very plausible but false decodes.
> > > These appeared much more frequently than they do on OPDS which in
> > > any case gives enough additional information on signal quality to
> > > be able to spot most false decodes. It's a nice idea, but the
> > > real/false threshold is set much too far towards 'real', making
> > > the resultant information next to useless.
> > >
> > > And what is the "200%" fade figure all about? I am 1000% sure I
> > > don't know.
> > >
> > > Mike, G3XDV
> > > ==========
> > >
> > >> All,
> > >>
> > >> Other  than  the  odd  false  spot , that looked to  be  quite  a
> > >> good  launch  for the  new  addition  to  Opera
> > >>
> > >> Nothing  can be  100% ,   Dynamic   detections ,  will  show   1
> > >> minuet after  conventional OP8   and   4  minuets   after  a
> > >> conventional  OP32  decode , this  is due  to  data  processing
> > >> time and  is a  fixed  off  set  , Time can be  used  as  a
> > >> reality
> > >>  check .
> > >>
> > >> Dynamic  compares   Call Signs  with  activity , to provide  the
> > >> lowest  possible  detection  levels , to  do  this  ,  Opera
> > >> changes mode  to  give  a  second  chance  detection , based on
> > >> s/n , The detection  threshold has been  set  to  give a good
> > >> working compromise between  real and  false detections.
> > >>
> > >>  Noting , each individual transmission is  processed 
> > >>  independently , Conventional  and Dynamic  processes  are   
> > >>  running  in parallel
> > >>
> > >> 73-Graham
> > >> G0NBD
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> From: Graham
> > >> Sent: Tuesday, January 06, 2015 8:38 PM
> > >> To: [email protected]
> > >> Subject: LF: New version OPERA >> ''Opera Dynamic'' <<
> > >>
> > >>
> > >> New  version  of  opera  up-loaded
> > >>
> > >> Opera Dynamic: Introduces   the  first, adaptive  multi mode
> > >> Beacon decoding/detection  system , seamlessly  taking over from 
> > >> the  Opera data  decoder  and  dynamically configuring  the  low
> > >> level  detector.
> > >>
> > >>
> > >>
> > >> Opera Dynamic  is  configured  for  MF OP8  and  LF OP32   ,
> > >> providing
> > >>  a dynamically   configured  low  level  detection  mode ,
> > >> complimenting  the  Opera  Data mode ,
> > >>
> > >>
> > >>
> > >> Opera Dynamic  forms  part  of  the  windows  distributed 
> > >> package ,
> > >>
> > >>
> > >>
> > >> 73-Graham
> > >>
> > >> G0NBD
> > >>
> > >>
> > >>
> > >>
> > >>
> > >> UPLOAD
> > >>
> > >>
> > >>
> > >>   http://rosmodem.wordpress.com/
> > >>
> > >>
> > >>
> > >> SUPPORT
> > >>
> > >>
> > >>
> > >> https://groups.yahoo.com/neo/groups/O_P_E_R_A_/info
> > >>
> > >>
> > >>
> > >> https://www.facebook.com/groups/operadatamode/
> > >>
> > >>
> > >>
> > >> -----
> > >> No virus found in this message.
> > >> Checked by AVG - www.avg.com
> > >> Version: 2015.0.5577 / Virus Database: 4257/8885 - Release Date:
> > >> 01/07/15
> > >>
> > >
> > >
> > > 
> > 
> > 
> > 
> > -----
> > No virus found in this message.
> > Checked by AVG - www.avg.com
> > Version: 2015.0.5577 / Virus Database: 4257/8885 - Release Date:
> > 01/07/15
> > 
> 
> 
> 
> 
> 
> -----
> No virus found in this message.
> Checked by AVG - www.avg.com
> Version: 2015.0.5577 / Virus Database: 4257/8885 - Release Date:
> 01/07/15
> 



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