Re: Linrad and JT65

Joe,

At 10:16 AM 11/30/2006 -0500, you wrote:
---snipped---
>When a full minute of data is available, MAP65 scans the 
>full 90 kHz (or any designated portion) looking for JT65 
>signals, which are easily recognized by the software because 
>of the known pseudo-random pattern of their sync tones.  For 
>each detected JT65 signal, the program "peaks up" to find 
>the best-fit values of frequency, time delay DT, and linear 
>polarization angle.  It then decodes the received message. 
>The results are displayed in the form of a "band map" that 
>looks something like the following (based on a particular 
>segment of recorded data that I have been using for tests):
>
>   Freq    DF   DT   UTC Seq   Message                KV  DS
>-----------------------------------------------------------
>144.114   -4  2.6  1753  2 #  WA4EWV RK3FG KO86  OOO  1   0
>144.127  340  2.7  1753  2 *  CQ KB8RQ EM79           1  10
>144.129  204  2.7  1753  2 *  QRZ W5UN EM23           1   0
>144.131  234  2.6  1754  1 *  CQ S52LM JN65           1  10
>144.133 -281  2.7  1754  1 *  CQ 9H1TX JM75           1  10
>144.145  -14  0.3  1753  2 *  OK1TEH K5GMX FN31       1   0
>144.147 -250  2.7  1754  1 *  CQ EA2AGZ IN91          1  10

I would like display of the peak polarity angle received as my Tx pol is
discrete: H/V and this would help in prediction of best Tx pol.  I have
separate RX and Tx polarity selection.  Perhaps Linrad does this
already...just begining using Linrad.

>The band map presents a list showing the most recent decoded 
>message at each frequency containing a JT65 signal.  The 
>list is sorted in order of increasing frequency, and is 
>updated every minute; at a given frequency (within a 
>specified tolerance) only the most recent decoded message is 
>shown.  With some effort put into a user interface, decoding 
>histories at each frequency cold be made available optionally.

Not sure if I understand the last paragraph, but I can see that one could
have a rapid accumulation of data each minute so some kind of sliding
window (say ten minutes) is needed to drop off old data or archive changes
in datums, or ???

>MAP65 is still very much in development, but all of its 
>essentials are in place and working well.  The program 
>automatically finds and decodes all detectable JT65 signals 
>in a 90 kHz slice of a band -- and it does this in well 
>under a minute, so that it can keep up in real time. 
>Sensitivity is the same as that afforded by WSJT for a 
>single received signal.

That is cool.  Will MAP65 adapt to SDR's that acquire more than 90 KHz BW,
The SDR-IQ displays up to 190 KHz.  For JT65 covering the JA window up to
144.170 would exceed 90 KHz a little.

>I would appreciate any feedback or suggestions from other 
>users or potential users of Linrad and JT65.  Based on this 
>brief description of MAP65, would you use such a Linrad 
>add-on if it were made available?  If so, what else would 
>you want it to do?

Absolutely!

73's,
Ed - KL7UW  
=========================================
http://www.qsl.net/al7eb - BP40iq 
144-EME: FT-847, mgf-1801/1402, 4xM2-xpol-20, 170w
432-EME: FT-847, mgf-1402, 1x21-ele (18.6 dBi), 60w
USA Rep. for Dubus Magazine: dubususa@...
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