Correct frequency scale for nes FFT length. (Still off by a bit??)

git-svn-id: svn+ssh://svn.code.sf.net/p/wsjt/wsjt/branches/wsjtx@2644 ab8295b8-cf94-4d9e-aec4-7959e3be5d79

jtms3.txt

@@ -1,50 +0,0 @@
-	JTMS v3.0: Possible New Mode for Meteor Scatter
-	-----------------------------------------------
-
-1. Transmitting
-
-Messages are sent character-by character, 6 bits plus even parity.
-Message length can be one of {5 7 9 11 13 17 19 23 29}; messages are
-padded with blanks up to the next available length.  
-
-Modulation is BPSK at 2000 baud.  The baseband waveform is built by
-inserting a tapered sinc function for each bit, then multiplying by a
-sine wave at frequency f0 = 10000.0/7 = 1428.57 Hz.  At fsample=48000
-Hz there are 24 samples per PSK symbol and 7*24=168 samples per
-character.  Carrier phase increment over one character is
-f0*(168/48000) = 5 cycles, exactly.
-
-2. Receiving
-
-  a. Pings are detected (or mouse-picked data is selected) as in
-     WSJT9.  Pings can also be detected from the squared analytic
-     signal.  Experience may tell which is better.
-
-  b. Compute real-to-complex FFT.  Zap birdies, remove frequency 
-     components outside the range 300 - 2700 Hz, and convert to analytic
-     time-domain signal.  (analytic)
-
-  c. Square the complex signal, cx2=cx*cx, and compute FFT.  Look for
-     carrier at frequency 3000 + 2*DF +/- 2*Tol.  (msdf)
-
-  d. If carrier is found, measure frequency f and phase phi.  Multiply
-     cx by exp(-twopi*i*f*t - phi) to recover the real baseband signal
-     x() to within a sign ambiguity.  (tweak1)
-
-  e. Apply matched filter for the Tx pulse shape to x().  This is
-     essentially a rectangular BPF, -1000 to +1000 Hz ?  (Or convolve
-     with the generated PSK pulse shape, the tapered sinc() function.)
-
-  f. Establish symbol and character sync by cross-correlating with
-     conjg(cwb), where cwb is the baseband PSK waveform for the
-     <space> character.
-
-  g. Find message length by computing ACF (of what?  cdat?  soft
-     symbol values?)
-
-  h. Decode the message by cross-correlating character-length segments
-     of cdat against complex waveforms for each possible character.
-
-  i. If msglen is established and long enough, try folding the data and
-     determining best-fit characters as above.
-

mainwindow.cpp

@@ -335,7 +335,7 @@ void MainWindow::dataSink(int k)
   lab4->setText(t);
   ui->xThermo->setValue((double)px);   //Update the thermometer
   if(m_monitoring || m_diskData) {
-    g_pWideGraph->dataSink2(s,ihsym,m_diskData,lstrong);
+    g_pWideGraph->dataSink2(s,df3,ihsym,m_diskData,lstrong);
   }
 
   //Average over specified number of spectra

plotter.cpp

@@ -152,8 +152,8 @@ void CPlotter::UTCstr()
 {
   int ihr,imin,isec;
   if(jt9com_.ndiskdat != 0) {
-    ihr=jt9com_.nutc/10000;
-    imin=(jt9com_.nutc/100) % 100;
+    ihr=jt9com_.nutc/100;
+    imin=jt9com_.nutc % 100;
   } else {
     qint64 ms = QDateTime::currentMSecsSinceEpoch() % 86400000;
     imin=ms/60000;
@@ -241,7 +241,6 @@ void CPlotter::DrawOverlay()                                 //DrawOverlay()
   painter0.setFont(Font);
   painter0.setPen(Qt::black);
 
-  m_fftBinWidth=12000.0/m_nsps;
   if(m_binsPerPixel < 1) m_binsPerPixel=1;
   m_fSpan = w*df;
   int n=m_fSpan/10;
@@ -579,6 +578,11 @@ double CPlotter::fGreen()
 void CPlotter::setNsps(int n)                                  //setNSpan()
 {
   m_nsps=n;
+  m_fftBinWidth=1500.0/1024.0;
+  if(m_nsps==15360)  m_fftBinWidth=1500.0/2048.0;
+  if(m_nsps==40960)  m_fftBinWidth=1500.0/6144.0;
+  if(m_nsps==82944)  m_fftBinWidth=1500.0/12288.0;
+  if(m_nsps==252000) m_fftBinWidth=1500.0/32768.0;
   DrawOverlay();                         //Redraw scales and ticks
   update();                              //trigger a new paintEvent}
 }

widegraph.cpp

@@ -65,19 +65,19 @@ void WideGraph::saveSettings()
   settings.endGroup();
 }
 
-void WideGraph::dataSink2(float s[], int ihsym, int ndiskdata,
+void WideGraph::dataSink2(float s[], float df3, int ihsym, int ndiskdata,
                           uchar lstrong[])
 {
   static float splot[NSMAX];
   float swide[2048];
   float smax;
-  double df;
+//  double df;
   int nbpp = ui->widePlot->binsPerPixel();
   static int n=0;
   static int nkhz0=-999;
   static int ntr0=0;
 
-  df = 12000.0/m_nsps;
+//  df = 12000.0/m_nsps;
 
   //Average spectra over specified number, m_waterfallAvg
   if (n==0) {

widegraph.h

@@ -16,7 +16,7 @@ public:
 
   double m_dialFreq;
 
-  void   dataSink2(float s[], int ihsym, int ndiskdata,
+  void   dataSink2(float s[], float df3, int ihsym, int ndiskdata,
                    uchar lstrong[]);
   int    QSOfreq();
   int    nSpan();