diff --git a/station/tools/baseband_spectogram.py b/station/tools/baseband_spectogram.py
index 58b7e67..bd838a8 100644
--- a/station/tools/baseband_spectogram.py
+++ b/station/tools/baseband_spectogram.py
@@ -11,7 +11,7 @@ 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('-fc', '--centralFreq', type=float, help='sets the sample rate [hz]')
+ cliParser.add_argument('-fc', '--centralFreq', type=float, help='sets center freq of spectrum [hz]')
cliParser.add_argument('-f', '--format', type=str,
help='Output format',
@@ -30,10 +30,21 @@ if __name__ == '__main__':
num_rows = len(data) // fft_size // sampleSize
# ok compute how many data to one row
- num_rows_real = 100
+ num_rows_real = 1024
if num_rows < num_rows_real:
num_rows_real = num_rows
+ # find DC part
+ DC_PART = 0
+ for i in range(num_rows):
+ 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
+ DC_PART += np.sum(subdata)
+
+ DC_PART /= num_rows * fft_size
+
abstract_rows_per_row = int(num_rows / num_rows_real)
spectrogram = np.zeros((num_rows_real, fft_size))
@@ -45,6 +56,7 @@ if __name__ == '__main__':
subdata = data[subdata_start : subdata_start + fft_size * sampleSize]
subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+ sub_fft -= DC_PART # remove DC part
cur_fft = 10 * np.log10(np.abs(np.fft.fftshift(np.fft.fft(subdata)))**2)
diff --git a/station/tools/cw_morse.py b/station/tools/cw_morse.py
index 704ae2b..198bda9 100644
--- a/station/tools/cw_morse.py
+++ b/station/tools/cw_morse.py
@@ -1,11 +1,12 @@
#!/usr/bin/env python
-# Simple CW morse decoder
+# Simple spectogram ploter
import argparse
import numpy as np
+import matplotlib.pyplot as plt
if __name__ == '__main__':
- cliParser = argparse.ArgumentParser(description='Simple CW morse decoder')
+ cliParser = argparse.ArgumentParser(description='Simple spectogram ploter')
cliParser.add_argument('input_file', type=str, help='input filename baseband record')
cliParser.add_argument('output_file', type=str, help='output filename decoded text')
@@ -34,42 +35,65 @@ if __name__ == '__main__':
failChar = args.failChar
downSample = int(sample_rate // down_rate)
+ sampleSize = 2
- data = data[1::2] + 1j * data[0::2]
- data = data[1::downSample] # downsample
- data = data - np.mean(data) # normalize
+ num_rows = len(data) // (fft_size * sampleSize * downSample)
+ num_samples = len(data) // (sampleSize * downSample)
- num_rows = len(data) // fft_size
-
- beep_trashold = []
-
+ DC_PART = 0
for i in range(num_rows):
- fft = np.abs(np.fft.fftshift(np.fft.fft(data[i*fft_size:(i+1)*fft_size])))
- frame_max = np.max(fft[len(fft)//2 - bandwidth//2 + offset_freq : len(fft)//2 + bandwidth//2 + offset_freq])
- beep_trashold.append(frame_max)
+ subdata_start = i * sampleSize * fft_size * downSample
+ subdata = data[subdata_start : subdata_start + fft_size * sampleSize * downSample]
+
+ subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+ subdata = subdata[0::downSample] # downsample
+ DC_PART += np.sum(subdata)
- beep_trashold = np.mean(beep_trashold)
+ DC_PART /= num_samples
+
+ print(f"DC part is {DC_PART}")
+
+ beep_trashold = 0
- beep = np.zeros(num_rows)
-
for i in range(num_rows):
- fft = np.abs(np.fft.fftshift(np.fft.fft(data[i*fft_size:(i+1)*fft_size])))
+ subdata_start = i * sampleSize * fft_size * downSample
+ subdata = data[subdata_start : subdata_start + fft_size * sampleSize * downSample]
+
+ subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+ subdata = subdata[0::downSample] # downsample
+ subdata -= DC_PART
+
+ fft = np.abs(np.fft.fftshift(np.fft.fft(subdata)))
frame_max = np.max(fft[len(fft)//2 - bandwidth//2 + offset_freq : len(fft)//2 + bandwidth//2 + offset_freq])
- if (frame_max >= beep_trashold):
- beep[i] = 1
-
+ beep_trashold += frame_max
+
+ beep_trashold /= num_rows
+
+ print(f"beep trashold is {beep_trashold}")
+
+
is_one = False
mean_one_len = []
mean_zero_len = []
sig_len = 0
- for signal in beep:
- if signal == 1 and not(is_one):
+ for i in range(num_rows):
+ subdata_start = i * sampleSize * fft_size * downSample
+ subdata = data[subdata_start : subdata_start + fft_size * sampleSize * downSample]
+
+ subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+ subdata = subdata[0::downSample] # downsample
+ subdata -= DC_PART
+
+ fft = np.abs(np.fft.fftshift(np.fft.fft(subdata)))
+ frame_max = np.max(fft[len(fft)//2 - bandwidth//2 + offset_freq : len(fft)//2 + bandwidth//2 + offset_freq])
+
+ if (frame_max >= beep_trashold) and not(is_one):
mean_zero_len.append(sig_len)
sig_len = 0
is_one = True
-
- if signal == 0 and is_one:
+
+ if (frame_max < beep_trashold) and is_one:
mean_one_len.append(sig_len)
sig_len = 0
is_one = False
@@ -82,9 +106,19 @@ if __name__ == '__main__':
is_one = False
morse = ""
sig_len = 0
-
- for signal in beep:
- if signal == 1 and not(is_one):
+
+ for i in range(num_rows):
+ subdata_start = i * sampleSize * fft_size * downSample
+ subdata = data[subdata_start : subdata_start + fft_size * sampleSize * downSample]
+
+ subdata = subdata[1::2] + 1j * subdata[0::2] # convert to complex
+ subdata = subdata[0::downSample] # downsample
+ subdata -= DC_PART
+
+ fft = np.abs(np.fft.fftshift(np.fft.fft(subdata)))
+ frame_max = np.max(fft[len(fft)//2 - bandwidth//2 + offset_freq : len(fft)//2 + bandwidth//2 + offset_freq])
+
+ if (frame_max >= beep_trashold) and not(is_one):
is_one = True
if sig_len >= mean_zero_len * 2:
morse += "\n"
@@ -92,15 +126,15 @@ if __name__ == '__main__':
morse += " "
sig_len = 0
-
- if signal == 0 and is_one:
+
+ if (frame_max < beep_trashold) and is_one:
is_one = False
if sig_len > mean_one_len:
morse += "-"
else:
morse += "."
sig_len = 0
-
+
sig_len += 1