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Re: LF: Opera decode

To: <[email protected]>
Subject: Re: LF: Opera decode
From: "Graham" <[email protected]>
Date: Mon, 18 Jan 2016 22:12:17 -0000
Importance: Normal
In-reply-to: <[email protected]>
References: <[email protected]> <F6DE9D64E261486DA454671269E47857@AGB> <[email protected]>
Reply-to: [email protected]
Sender: [email protected]
L,

Yes, that's the problem, if the Tx site is 'remote' , well not a problem if you fire the opera decoder -40 and above , then you have a data decode, call sign, s/n, % fade and frequency , but if there is only a single Rx , and only a dynamic spot then its back to basic's ....may be a TX beacon in the psk-map data base .

Simple work around is to run a local decode [ can be audio from the app or off air ] to give the system a time stamp, cheap $10 dongle in direct sample works fine, just on leakage..

73-G,

--------------------------------------------------
From: "Laurence KL7 L" <[email protected]>
Sent: Monday, January 18, 2016 9:46 PM
To: <[email protected]>
Subject: Re: LF: Opera decode

We did the same sort of thing a few days back to validate ja5np decode of xpq - time and exact frequency were good...

L

On Jan 18, 2016, at 12:40, Graham <[email protected]> wrote:

John,

''Decode from LA4ANA''  -

That is the  output from the  dynamic DETECTOR  , ie  pattern matching
correlation detector, provided as a second lower s/n detection system,
should the  Opera DECODER fail  to recover the  transmission.
lower limit for op32 ~ -40 dB s/n

The Dynamic detector attempts to 'pattern match' the Tx 010100 profile ,a primitive 'Painting by numbers' system if you like, dynamic is set to give ~ -6 dB
advantage.

The issue of false detection/real call signs is addressed in the Opera Dynamic system and the system output, clearly indicates when the spot is Opera or Dynamic, validated
or not.

False opera  decode =  call  sign format  'random characters'
False  dynamic detection  =  call  sign from  list ,  wrong  time  stamp

Deep Search ?? =   Not Validated

In the  case of a  non-validation '??'  ,

its  to the  users to evaluate the  situation ,
was the  station  sending ?
is the  frequency  that  of the  detected station ?
is the  time  stamp  aligned  with the  expected Tx ?

Issues with the psk-map seem to be a common theme, the system uploads have not
changed , but  map-housekeeping routines  could be  removing  swl markers

73-Graham
G0NBD







--------------------------------------------------
From: "John Gibbs" <[email protected]>
Sent: Monday, January 18, 2016 4:28 AM
To: <[email protected]>
Subject: LF: Opera decode

Decode from LA4ANA just after local sunset here.. was this station even
on air at 18_0141 utc ??? Must be bogus.
Anyone know why version of  Opera v1.5.8 on LF or MF  would not show on
PSK map.  Earlier versions used to.

03:06    136 WE2XPQ de VE7BDQ Op32 Deep Search ?? 2147 km -43 dB in
SOUTHDELTA BC 1474.1 Hz with 10w + Marconi
01:41 136 LA4ANA de VE7BDQ Op32 Deep Search ?? -42 dB in SOUTHDELTA BC
1531.3 Hz
***********  18/01/2016  ***********

73  John / VE7BDQ



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