Scope and channel analyzer: new squared magnitude (linear power) projection mainly for radioastronomy

debian/changelog

@@ -3,6 +3,7 @@ sdrangel (4.0.1-1) unstable; urgency=medium
   * DSD demod: added NXDN support
   * DATV demod: include it only if FFmpeg > 3.1 is installed
   * Fixes for Arch. Manual merge of pull request #183
+  * Scope: new magnitude squared projection mainly for radioastronomy
 
  -- Edouard Griffiths, F4EXB <f4exb06@gmail.com>  Sat, 23 Jun 2018 09:14:18 +0200
   

plugins/channelrx/chanalyzer/chanalyzerplugin.cpp

@@ -23,7 +23,7 @@
 
 const PluginDescriptor ChannelAnalyzerPlugin::m_pluginDescriptor = {
 	QString("Channel Analyzer"),
-	QString("4.0.0"),
+	QString("4.0.1"),
 	QString("(c) Edouard Griffiths, F4EXB"),
 	QString("https://github.com/f4exb/sdrangel"),
 	true,

plugins/channelrx/chanalyzer/readme.md

@@ -9,9 +9,14 @@ This plugin can be used to analyze the complex signal received in its passband.
   - Real part
   - Imaginary part
   - Magnitude linear
+  - Power i.e. squared magnitude linear
   - Power i.e. squared magnitude log (dB)
   - Phase
   - Phase derivative (instant frequency)
+  - BPSK symbol mapping
+  - QPSK symbol mapping
+  - 8-PSK symbol mapping
+  - 16-PSK symbol mapping
   
 The same waveforms can be used to trigger the scope trace
 
@@ -211,6 +216,7 @@ To construct a trace which represents real values the incoming complex signal mu
   - Real: take the real part
   - Imag: take the imaginary part
   - Mag: calculate magnitude in linear representation. This is just the module of the complex sample
+  - MagSq: calculate power in linear representation. This is the squared module of the complex sample
   - MagDB: calculate power in log representation as 10*log10(x) or decibel (dB) representation. This is the squared module of the complex sample expressed in decibels
   - Phi: instantaneous phase. This is the argument of the complex sample.
   - dPhi: instantaneous derivative of the phase. This is the difference of arguments between successive samples thus represents the instantaneous frequency.
@@ -283,6 +289,7 @@ The top slider is a coarse adjustment. Each step moves the trace by an amount th
 
   - Real, Imag: 0.01
   - Mag: 0.005
+  - MagSq: 0.005
   - MagDB: 1 dB
   - Phi, dPhi: 0.01
 
@@ -290,6 +297,7 @@ The bottom slider is a fine adjustment. Each step moves the trace by an amount t
 
   - Real, Imag: 50.0E-6
   - Mag: 25.0sE-6
+  - MagSq: 25.0sE-6
   - MagDB: 0.01 dB
   - Phi, dPhi: 50.0E-6
 
@@ -370,6 +378,7 @@ The top slider is a coarse adjustment. Each step moves the trigger level by an a
 
   - Real, Imag: 0.01
   - Mag: 0.005
+  - MagSq: 0.005
   - MagDB: 1 dB
   - Phi, dPhi: 0.01
   
@@ -377,6 +386,7 @@ The bottom slider is a fine adjustment. Each step moves the trigger level by an
 
   - Real, Imag: 50.0E-6
   - Mag: 25.0sE-6
+  - MagSq: 25.0sE-6
   - MagDB: 0.01 dB
   - Phi, dPhi: 50.0E-6
   

sdrbase/dsp/projector.cpp

@@ -52,6 +52,13 @@ Real Projector::run(const Sample& s)
             v = std::sqrt(magsq);
         }
             break;
+        case ProjectionMagSq:
+        {
+            Real re = s.m_real / SDR_RX_SCALEF;
+            Real im = s.m_imag / SDR_RX_SCALEF;
+            v = re*re + im*im;
+        }
+            break;
         case ProjectionMagDB:
         {
             Real re = s.m_real / SDR_RX_SCALEF;

sdrbase/dsp/projector.h

@@ -25,6 +25,7 @@ public:
         ProjectionReal = 0, //!< Extract real part
         ProjectionImag,     //!< Extract imaginary part
         ProjectionMagLin,   //!< Calculate linear magnitude or modulus
+        ProjectionMagSq,    //!< Calculate linear squared magnitude or power
         ProjectionMagDB,    //!< Calculate logarithmic (dB) of squared magnitude
         ProjectionPhase,    //!< Calculate phase
         ProjectionDPhase,   //!< Calculate phase derivative i.e. instantaneous frequency scaled to sample rate

sdrgui/dsp/scopevisng.cpp

@@ -463,6 +463,11 @@ int ScopeVisNG::processTraces(const SampleVector::const_iterator& cbegin, const
                 {
                     v = ((*itCtl)->m_projector.run(*begin) - itData->m_ofs)*itData->m_amp - 1.0f;
                 }
+                else if (projectionType == Projector::ProjectionMagSq)
+                {
+                    v = ((*itCtl)->m_projector.run(*begin) - itData->m_ofs)*itData->m_amp - 1.0f;
+                    // TODO: power display overlay for squared magnitude
+                }
                 else if (projectionType == Projector::ProjectionMagDB)
                 {
                     Real re = begin->m_real / SDR_RX_SCALEF;

sdrgui/gui/glscopeng.cpp

@@ -1877,6 +1877,7 @@ void GLScopeNG::setYScale(ScaleEngine& scale, uint32_t highlightedTraceIndex)
         scale.setRange(Unit::Decibel, pow_floor, pow_floor + pow_range);
         break;
     case Projector::ProjectionMagLin:
+    case Projector::ProjectionMagSq:
         if (amp_range < 2.0) {
             scale.setRange(Unit::None, amp_ofs * 1000.0, amp_range * 1000.0 + amp_ofs * 1000.0);
         } else {

sdrgui/gui/glscopenggui.cpp

@@ -1021,7 +1021,7 @@ void GLScopeNGGUI::setAmpOfsDisplay()
     {
         double a;
 
-        if (projectionType == Projector::ProjectionMagLin)
+        if ((projectionType == Projector::ProjectionMagLin) || (projectionType == Projector::ProjectionMagSq))
         {
             a = o/2000.0f;
         }
@@ -1087,7 +1087,7 @@ void GLScopeNGGUI::setTrigLevelDisplay()
     {
         double a;
 
-        if (projectionType == Projector::ProjectionMagLin) {
+        if ((projectionType == Projector::ProjectionMagLin) || (projectionType == Projector::ProjectionMagSq)) {
             a = 1.0 + t;
         } else {
             a = t;
@@ -1184,6 +1184,7 @@ void GLScopeNGGUI::fillProjectionCombo(QComboBox* comboBox)
     comboBox->addItem("Real", Projector::ProjectionReal);
     comboBox->addItem("Imag", Projector::ProjectionImag);
     comboBox->addItem("Mag", Projector::ProjectionMagLin);
+    comboBox->addItem("MagSq", Projector::ProjectionMagSq);
     comboBox->addItem("MagdB", Projector::ProjectionMagDB);
     comboBox->addItem("Phi", Projector::ProjectionPhase);
     comboBox->addItem("dPhi", Projector::ProjectionDPhase);
@@ -1225,7 +1226,7 @@ void GLScopeNGGUI::fillTraceData(ScopeVisNG::TraceData& traceData)
     traceData.m_ofsCoarse = ui->ofsCoarse->value();
     traceData.m_ofsFine = ui->ofsFine->value();
 
-    if (traceData.m_projectionType == Projector::ProjectionMagLin) {
+    if ((traceData.m_projectionType == Projector::ProjectionMagLin)  || (traceData.m_projectionType == Projector::ProjectionMagSq)) {
         traceData.m_ofs = ((10.0 * ui->ofsCoarse->value()) + (ui->ofsFine->value() / 20.0)) / 2000.0f;
     } else {
         traceData.m_ofs = ((10.0 * ui->ofsCoarse->value()) + (ui->ofsFine->value() / 20.0)) / 1000.0f;