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Re: LF: RE: Odd sunset captures

To: [email protected]
Subject: Re: LF: RE: Odd sunset captures
From: Eric NO3M <[email protected]>
Date: Thu, 3 Sep 2015 15:34:45 -0400
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As Tobias correctly points out, the erroneous decode Mike experienced was a result of correlation with a previous, correctly decoded signal from DK7FC.  This permits correlating partial data transmissions, such as when compound calls or XXNNxx grids are used that cannot be encoded in a single transmission.  There should be a expiration on the hash-table, but apparently not, since it's probably been quite a while since Mike actually decoded transmissions from Stefan on 630M.  This is not a correlation decode from a user created or Internet derived callsign list.

The idea of correlating signals against a user created or Internet derived callsign list is silly in the context of what WSPR is intended for.  WSPR is more or less a scientific instrument, for the purpose of acquiring propagation data.  Sure, people use it for other agendas and get thrilled about deep decodes, but WSPR is not a player in the "how weak can we go" arms race.  Using a call list table would skew data and in the context of propagation, fringe decodes (-30 and below) are more noise than indicative.

OPERA and WSPR are like comparing apples and oranges.   Is OPERA a serious propagation tool... maybe in some cases.  Is there a historic database somewhere that one can download to perform propagation studies?

73 Eric NO3M / WG2XJM

On 09/03/2015 02:33 PM, Graham wrote:
Of course  Roman ,  can have  funny  wrong  call's  any data  mode  will  make those ,  more  funny  is  people  compare   data decoding  with  correlation detection  and  not  realise why   correlation has  lower   s/n  , and particularly  hilarious  is  those  who  know  what's  happening  and don't  tell  anyone .
Opera only  deploys  dynamic  on  477/136 , the  HF to SHF  are all  simply  data  decodes, where  as  the  Magic Mode has  mixed  correlation  and  decoding  on all  bands , which  explains  how it  survives  Doppler spreads  3 times  its  b/w  on 10 MHZ and even  works , some times  on vhf ..  mfsk can be correlated  , just the  same as  ook  ,   the  time  locking  has more to do  with  pattern  matching, than  decoding  data .
As some one  pointed out ,  'What ever colour the  cat , as long as  it  catches  the  mouse'  just in this  case , the  cat's  out of the bag and  it  turns out , there  are  more than  one  in there .
G , ,)

From: Roman
Sent: Thursday, September 03, 2015 7:08 PM
Subject: Re: LF: RE: Odd sunset captures

Graham I rx too mny false and fantoms in OPERA for long 3 years.
As usual this is not real calls.
03.09.2015, 19:20, "Graham" <[email protected]>:
That's  interesting  Luis  those  . the  kings  not  wearing  anything   moment's  jiji
By the  qrg 400k  , this  was a  wspr  2  TX ?
So the  only  way  Stefan's  call  sign  could be  recovered   is from the  look  up  table as  part of a  correlation  process [ see other  linking posts]
Its  IMPOSSIBLE   for  Opera  to  produce  such false  Decode 
But if you  mean  DYNAMIC Detection  , has  Ghosts ,  that's  true for  any  correlation  system   and the  ghosts always  take on real life  forms 
However the  Phantom , has  provided  a  Time  stamp   Ghost  Buster  validation  system  . something  wspr cannot as it  already uses the  web  for  time  locking , oddly , accurate  time is required for  a  correlation  system ...
People  are  not  too  sure  of the  difference  between  Decode  and Detection  ,    but those  who do , like the  extra  dB's one  gives  over the  other 
As I  noted  previously 
''no  one minds a  bit of the   'Old Jaspers'  as  long as its not take too  seriously''
6 meters  is  known as the  Magic  band ,  may be  wspr  should be   the  'Magic'   Mode 
Sent: Thursday, September 03, 2015 11:28 AM
Subject: LF: RE: Odd sunset captures
Hi Mike, MF
From my records last night, DK7FC was transmiting in 06-16-26-36 ... periods, but not at 23:04
The locator shown in your decode is also wrong
The closest frame to the time you decoded was at 23:06
2306 -21 -1.2 0.475684 0 DK7FC JN49 30
Not only Opera has its ghost ! ;-)
PS: I'm QRV again. Back from a 15 days vacation trip
73 de Luis

De: [email protected] [mailto:[email protected]] En nombre de Michael Sapp
Enviado el: jueves, 03 de septiembre de 2015 2:19
Para: [email protected]; [email protected]
Asunto: LF: Odd sunset captures
Hi All: I'm not sure what to think of this....
I have been experimenting with IF shifting my radio to get WG2XJM very strong signal 10 to 13 dB down the IF bandpass
curve to improve weak signal reception of other stations when Eric is transmitting.  Odd sunset partial captures appear
to be transatlantic, but I am not sure about reality with this data. My EWE antenna was configured to favor a SE direction, but with
120 degree 3dB beam width pattern it covers the NE as well.   Long distance transition zone propagation is a possibility, but I
would be hesitant to claim it not having received correct grid square information......
73, Mike wa3tts
Roman, RW3ADB

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