Hi Steve,
I'm happy to see that our test results are fully consistent. I look
forward to seeing how well sfrsd will perform in WSJT10 -- and
subsequently how much we can improve the JT65 decoding sensitivity in
WSJT-X.
-- Joe, K1JT
On 9/23/2015 9:02 PM, Steven Franke wrote:
> Thanks Joe -
> Your results in cases 1,3,4,5,7 agree with mine, to within a few decodes
> either way. All of my runs were on OS X with sfrsd compiled using gcc - but
> perhaps this produces a different set of random erasure vectors than either
> linux or windows. Just now, I’ve also confirmed your result from case 9 as
> well, running WSJT10 in a virtual Ubuntu 14.04 machine running under VMware
> on OS X. I got 813 total decodes (BM+KVASD). Wow. I was feeling pretty good
> about sfrsd until I saw that result.
>
> I will poke around at this and see what I can figure out. Thanks for taking
> time out to confirm my results! - it gives me a lot more confidence about
> what I’m doing over here.
> Steve k9an
>
>> On Sep 23, 2015, at 3:13 PM, Joe Taylor<j...@princeton.edu> wrote:
>>
>> Hi Steve and all,
>>
>> Here's an update on my tests of decoding weak JT65A signals. I used
>> 1000 files generated by SimJT, each containing one JT65A signal at
>> S/N = -24 dB. I am using current code revisions of WSJT-X v1.6.1 (with
>> minor edits noted below) and WSJT v10.0.
>>
>> For each line in the following table the final number is the number of
>> valid decodes. None of the tests yielded any false decodes.
>>
>> 1. WSJT-X (BM only) 2
>> 2. WSJT (BM only) 5
>> 3. WSJT-X + kvasd 189
>> 4. WSJT-X + kvasd (thresh0=1, ntest>0) 207
>> 5. WSJT-X + sfrsd (Linux) 302
>> 6. WSJT-X + sfrsd (Win32) 309
>> 7. WSJT-X + sfrsd (Linux, thresh0=1) 348
>> 8. WSJT-X + sfrsd (Win32, thresh0=1) 350
>> 9. WSJT + kvasd (Linux) 809
>> 10.WSJT + kvasd (Win32) 809
>>
>> Test 4 set thresh0=1.0 rather than 1.5 in jt65a.f90. Tests 5 and 6 used
>> Steve's small changes to demod64a.f90 and extract.F90. Tests 7 and 8
>> used these and also set thresh0=1.0. Tests 9 and 10 used the default
>> WSJT v10.0. I believe the small differences in tests 5-6 and 7-8 are
>> the result of using different random number generators in Linux and
>> Windows. (The resulting random numbers generate the stochastic erasure
>> patterns used in Steve's algorithm.)
>>
>> Unless I've made a mistake somewhere, these results show clearly that
>> for marginal, isolated signals, none of the decoding schemes currently
>> being tested in WSJT-X reach the sensitivity provided by WSJT 10.0.
>>
>> To me the decoding superiority of WSJT is surprisingly large, even
>> though it probably amounts to slightly less than 1 dB. (See, for
>> example, the steep curves for "percent copy vs. S/N" in Figure 4 of
>> http://physics.princeton.edu/pulsar/K1JT/JT65.pdf or Figure 2 of
>> http://physics.princeton.edu/pulsar/K1JT/K1JT_eme2006.pdf .)
>>
>> It seems we would be well advised to look in detail at the (probably
>> rather minor) code-tuning differences in the late stages of processing
>> JT65 signals in WSJT and WSJT-X. An important question will be whether
>> we can simultaneously obtain near-optimum weak-signal sensitivity along
>> with acceptable decoding speed and all-around performance in a band
>> filled with many signals.
>>
>> It should also be instructive to try sfrsd as the final JT65 decoding
>> step in WSJT 10.0.
>>
>> -- Joe, K1JT
>>
>> ------------------------------------------------------------------------------
>> Monitor Your Dynamic Infrastructure at Any Scale With Datadog!
>> Get real-time metrics from all of your servers, apps and tools
>> in one place.
>> SourceForge users - Click here to start your Free Trial of Datadog now!
>> http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140
>> _______________________________________________
>> wsjt-devel mailing list
>> wsjt-devel@lists.sourceforge.net
>> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
>
>
> ------------------------------------------------------------------------------
> Monitor Your Dynamic Infrastructure at Any Scale With Datadog!
> Get real-time metrics from all of your servers, apps and tools
> in one place.
> SourceForge users - Click here to start your Free Trial of Datadog now!
> http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140
> _______________________________________________
> wsjt-devel mailing list
> wsjt-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/wsjt-devel
------------------------------------------------------------------------------
Monitor Your Dynamic Infrastructure at Any Scale With Datadog!
Get real-time metrics from all of your servers, apps and tools
in one place.
SourceForge users - Click here to start your Free Trial of Datadog now!
http://pubads.g.doubleclick.net/gampad/clk?id=241902991&iu=/4140
_______________________________________________
wsjt-devel mailing list
wsjt-devel@lists.sourceforge.net
https://lists.sourceforge.net/lists/listinfo/wsjt-devel
