I just captured a .c2 file after commenting out the call to timf2 in wspr_downsample and replacing x1 with x0 in the call to mixlpf. The dropouts are gone. So it looks like the problem is in timf2. Steve k9an
> On Jun 27, 2015, at 6:36 PM, Bill Somerville <g4...@classdesign.com> wrote: > > On 27/06/2015 23:58, Steven Franke wrote: > > Hi Steve, > >> Hi Joe - >> Yes, I am comfortable with making wsprd_exp the official wsprd. It has been >> working very well here. I had a couple of 16-decode cases again last night >> on 20 meters. >> >> Say, I just happened to be sitting here working on tracking down the signal >> dropouts. When you get a chance, would you please have a look at the images >> linked below: >> >> https://dl.dropboxusercontent.com/u/33211132/375Hzdata.png >> https://dl.dropboxusercontent.com/u/33211132/1500Hzdata.png >> >> The first one is absolute value of the complex 375 Hz data from a .c2 file >> plotted as a 108x400 pixel image. The dropouts are clearly seen along to the >> top of the image. >> >> The second one is the 1500 Hz c0 “common” data written from within the >> writec2.f90 function. The second image is (108*4)x400 pixels - and shows >> that the features have a 432-pt fundamental period (at 1500 Hz). >> >> I’m scratching my head over here trying to figure out how a pattern like >> this gets produced. Right now I’m looking at the wspr_downsample function, >> and specifically the lowpass filter function. Does this sound right to you? >> I’m not clear on what the timf2 function is doing - do you think that the >> problem could originate in there? > That's some funky custom filtering going on there! One thing that looks > wrong to me is that the variable 'nb' in wspr_downsample.f90 really > ought to be initialized, I'd guess to '0'. Having said that a quick > glance thought the code seems to imply that if 'nb' is zero then the > whole divide weak and strong frequencies in timf2.f90 may not achieve > anything. > > I may well be well of track here as my DSP knowledge is way short of > this sort of custom filtering code :( >> >> Steve > 73 > Bill > G4WJS. >> >> >>> On Jun 27, 2015, at 5:46 PM, Joe Taylor <j...@princeton.edu> wrote: >>> >>> Hi Steve, >>> >>> Sorry to be slow in getting back to you. After my post about wsprd_exp >>> I got involved in chasing a bug in the ISCAT decoder ... >>> >>> On 6/26/2015 12:31 PM, Steven Franke wrote: >>>> I’m glad to see that you were able to confirm the improved performance >>>> of the two-pass decoder. I’m guessing that your dataset includes a more >>>> representative mixture of bands and conditions than the group of >>>> 20m files that I used. Hence the smaller, but still significant, >>>> increase in the number of decodes over the default wsprd. >>> Probably so. I thought the increased number of decodes was very >>> worthwhile, anyway. >>> >>>> I am surprised by your observation that the two-pass decoder is faster >>>> than the default one. That’s not what I see here. Are you using your >>>> wspr_timer.out times? Or some other measure of execution time? >>>> The numbers that I reported were the “Total” times from wspr_timer.out. >>> I ran both tests a couple of times, and I also used the “Total” times >>> from wspr_timer.out. However, I was concentrating on decoder >>> performance rather than timing, so my observation needs a more careful >>> look before being taken very seriously. I hope to find time to look at >>> it more thoroughly next week, and maybe see if any further optimizations >>> are possible. >>> >>> Are you comfortable with making wsprd_exp the "official" wsprd now ? >>> >>> -- Joe > > > ------------------------------------------------------------------------------ > Monitor 25 network devices or servers for free with OpManager! > OpManager is web-based network management software that monitors > network devices and physical & virtual servers, alerts via email & sms > for fault. Monitor 25 devices for free with no restriction. Download now > http://ad.doubleclick.net/ddm/clk/292181274;119417398;o > _______________________________________________ > wsjt-devel mailing list > wsjt-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/wsjt-devel ------------------------------------------------------------------------------ Monitor 25 network devices or servers for free with OpManager! OpManager is web-based network management software that monitors network devices and physical & virtual servers, alerts via email & sms for fault. Monitor 25 devices for free with no restriction. Download now http://ad.doubleclick.net/ddm/clk/292181274;119417398;o _______________________________________________ wsjt-devel mailing list wsjt-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/wsjt-devel
