FFT on RPI

station/config.py

@@ -1,4 +1,4 @@
 masterUrl     = "http://10.0.0.8"
-apiKey        = "37c82347-f4fb-4552-950c-7e0767275eb6"
+apiKey        = "6f44206f-6d59-4761-b5a2-07172ecea2e6"
 pullInterval  = 120  # in sec
 planInterval  = 1200 # in sec

station/tools/baseband_spectogram.py

@@ -10,7 +10,7 @@ if __name__ == '__main__':
     
     cliParser.add_argument('input_file',  type=str, help='input filename')
     cliParser.add_argument('output_file', type=str, help='output filename')
-    cliParser.add_argument('-fs', '--sampleRate',  type=float, help='sets the sample rate [hz]')    
+    cliParser.add_argument('-fs', '--sampleRate', type=float, help='sets the sample rate [hz]')    
     cliParser.add_argument('-fc', '--centralFreq', type=float, help='sets the sample rate [hz]')    
     
     cliParser.add_argument('-f', '--format', type=str, 
@@ -20,22 +20,45 @@ if __name__ == '__main__':
 
     args = cliParser.parse_args()
     
-    data = np.fromfile(args.input_file, dtype=args.format)
-    
-    data = data[1::2] + 1j * data[0::2]
+    data = np.memmap(args.input_file, dtype=args.format, mode="r")
     
     fft_size    = 1024
-    sample_rate = args.sampleRate
-    Fc          = args.centralFreq
-    num_rows    = len(data) // fft_size # // is an integer division which rounds down
+    sampleSize  = 2 # I and Q
+        
+    sample_rate   = args.sampleRate
+    Fc            = args.centralFreq
+    num_rows      = len(data) // fft_size // sampleSize
+
+    # ok compute how many data to one row
+    num_rows_real = 100
+    if num_rows < num_rows_real:
+        num_rows_real = num_rows
+
+    abstract_rows_per_row = int(num_rows / num_rows_real)
     
-    spectrogram = np.zeros((num_rows, fft_size))
+    spectrogram = np.zeros((num_rows_real, fft_size))
     
-    for i in range(num_rows):
-        spectrogram[i,:] = 10 * np.log10(np.abs(np.fft.fftshift(np.fft.fft(data[i*fft_size:(i+1)*fft_size])))**2)
+    sub_fft = None
+    for i in range(abstract_rows_per_row * num_rows_real):
+
+        subdata_start = i * sampleSize * fft_size
+        subdata = data[subdata_start : subdata_start + fft_size * sampleSize]
+        
+        subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+        
+        cur_fft = 10 * np.log10(np.abs(np.fft.fftshift(np.fft.fft(subdata)))**2)
+            
+        if sub_fft is None:
+            sub_fft = cur_fft
+        else:
+            sub_fft = np.mean(np.array([cur_fft, sub_fft]), axis=0) 
+        
+        if i % abstract_rows_per_row == 0:
+            img_row = int(i // abstract_rows_per_row)
+            spectrogram[img_row,:] = sub_fft
+            sub_fft          = None
         
     fig = plt.figure(figsize=(5, num_rows / sample_rate * 20))
-    
     plt.imshow(spectrogram, cmap=plt.get_cmap('winter'), aspect='auto', extent = [sample_rate/-2/1e6 + Fc/1e6, sample_rate/2/1e6 + Fc/1e6, 0, len(data)/sample_rate], vmin=0, vmax=np.max(spectrogram))
     plt.xlabel("Frequency [MHz]")
     plt.ylabel("Time [s]")

web/seeds.php

@@ -12,6 +12,10 @@
     $leoWSatTape->name->set("Weather Satellite");
     $leoWSatTape->commit();
 
+    $nanosatelliteType = new \DAL\targetType();
+    $nanosatelliteType->name->set("Nanosatellite");
+    $nanosatelliteType->commit();
+
     $avhrrType = new \DAL\dataType();
     $avhrrType->name->set("AVHRR");
     $avhrrType->commit();
@@ -20,6 +24,10 @@
     $msumrType->name->set("MSU-MR");
     $msumrType->commit();
 
+    $telemetryType = new \DAL\dataType();
+    $telemetryType->name->set("Telemetry");
+    $telemetryType->commit();
+
     /**
      * Antennas seeds
      */
@@ -102,6 +110,10 @@
     $lrpt->name->set("LRPT");
     $lrpt->commit();
 
+    $cw = new \DAL\modulation();
+    $cw->name->set("CW");
+    $cw->commit();
+
     /**
      * Process pipes
      */
@@ -304,12 +316,37 @@
     $meteor23HRPT->antenna->set($qfh);
     $meteor23HRPT->commit();
 
+    $maxvalier = new \DAL\target();
+    $maxvalier->name->set("MAX VALIER SAT");
+    $maxvalier->type->set($nanosatelliteType);
+    $maxvalier->orbit->set("leo");
+    $maxvalier->description->set("");
+    $maxvalier->locator->set([
+        "tle" => [
+            "line1" => "1 42778U 17036P   23282.84620820  .00050788  00000-0  10567-2 0  9991",
+            "line2" => "2 42778  97.1421 315.3778 0008233  57.6254 302.5791 15.45432755350391"
+        ]
+    ]);
+    $maxvalier->commit();
+
+    $maxvalierCW = new \DAL\transmitter();
+    $maxvalierCW->target->set($maxvalier);
+    $maxvalierCW->dataType->set($telemetryType);
+    $maxvalierCW->bandwidth->set(120000);
+    $maxvalierCW->centerFrequency->set(145960000);
+    $maxvalierCW->modulation->set($cw);
+    $maxvalierCW->antenna->set($yagi);
+    $maxvalierCW->priority->set(0);
+    $maxvalierCW->processPipe->set($spectogramPipe);
+    $maxvalierCW->commit();
+
     // add autoplas
     $myStation137->autoPlan->set([
         $noaa15APT->id->get(),
         $noaa18APT->id->get(),
         $noaa19APT->id->get(),
-        $meteor23LRPT1->id->get()
+        $meteor23LRPT1->id->get(),
+        $maxvalierCW->id->get()
     ]);
 
     $myStation137->commit();