File:Wow signal spectrogram.svg

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Summary

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Description
English: Spectrogram of the "Wow! signal", taken from the intensities of the printout, with axes etc described in http://www.bigear.org/Wow30th/wow30th.htm Data hand-copied from http://www.bigear.org/Wow30th/WowL.jpg (by resizing it to same resolution as translucent text editor)
Date
Source Own work
Author Omegatron
SVG development
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This plot was created with Matplotlib.
Source code
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Python code

Source code 
import numpy as np
import matplotlib.pyplot as plt
import matplotlib.dates as mdates
from matplotlib.ticker import AutoMinorLocator
import datetime as dt

# "A space character on the printout denotes an intensity between 0 and 1"
d = {' ': 0}

# 'the numbers "1" to "9" denote the correspondingly numbered intensities'
for n in range(1, 10):
    d.update({str(n): n})

# 'intensities of 10 and above are indicated by a letter:
# "A" corresponds to intensities between 10 and 11,
# "B" to 11 to 12, and so on. The highest measured value was "U" (an intensity
# between 30 and 31), that is thirty times stronger than normal background
# noise.'
for n in range(10, 36):
    d.update({chr(65-10+n): n})

data = np.ones((82, 50), dtype=int)
with open('wow signal.txt', 'r') as f:
    for x, line in enumerate(f.readlines()[4:]):
        for y, c in enumerate(line[:50].strip('\n').ljust(50)):
            data[x, y] = d[c]

x_lims = [0.5, 50.5]  # Bin centers align with channel numbers

# August 15, 1977, Start: 22:04:10, Peak:  22:16:10, Stop:  22:20:21
# "Also, the EST on the printout referred to the end of the integration
# interval rather than the middle of that interval."
# So the center of each bin corresponds to these times - 5 seconds
y_lims = [dt.datetime(1977, 8, 15, 22, 20, 21-5),
          dt.datetime(1977, 8, 15, 22,  4, 10-5)]
y_lims = mdates.date2num(y_lims)

plt.figure(figsize=(5, 6))
plt.imshow(data, cmap='YlGnBu_r', aspect='auto',
           extent=[x_lims[0], x_lims[1],  y_lims[0], y_lims[1]])
cbar = plt.colorbar()
cbar.set_label('SNR')

ax = plt.gca()
ax.yaxis_date()
date_format = mdates.DateFormatter('%H:%M:%S')
ax.yaxis.set_major_formatter(date_format)
plt.yticks([dt.datetime(1977, 8, 15, 22, 6, 00),
            dt.datetime(1977, 8, 15, 22, 8, 00),
            dt.datetime(1977, 8, 15, 22, 10, 00),
            dt.datetime(1977, 8, 15, 22, 12, 00),
            dt.datetime(1977, 8, 15, 22, 14, 00),
            dt.datetime(1977, 8, 15, 22, 16, 00),
            dt.datetime(1977, 8, 15, 22, 18, 00),
            dt.datetime(1977, 8, 15, 22, 20, 00)])

plt.minorticks_on()
ax.yaxis.set_minor_locator(AutoMinorLocator(4))

plt.xlabel('Channel number')
plt.ylabel('EST [HH:MM:SS]')
plt.tight_layout()

Data

wow signal.txt 
CHANNEL NUMBER.(TWO DIGITS, WRITTEN VERTICALLY),  C RT. ASCEN.  DECLIN.   2ND LO   GLCTIC  GLCTIC  EASTERN    OBJECT
00000000011111111112222222222333333333344444444445 N  (1950.0)  (1950.0)    FREQ.    LAT     LONG   STD TIME
12345678901234567890123456789012345678901234567890 T  HH MM SS    DD MM    (MHz.)   (DEG.)  (DEG.)  HH MM SS

   2     1       1        1    21  1 1        1       19 05 22  - 27 02    120.162  -15.39   10.13  22 04 10
   1  21    1     12 1 11 1    11 1  1 1              19 05 37  - 27 02    120.163  -15.44   10.16  22 04 25
   1  1     1  2 1 1 1 1    11 1111   1      1        19 05 49  - 27 02    120.163  -15.45   10.18  22 04 37
  2 1    1        1    1  11 11  1   1                [too lazy to finish this part]
 12    1   1   1       1      1111   1
    1  1     1 11 1  1 1   1   111211
   12 21    1  21    1 1 1     11 21      2    1
   2  21    1  2 111   11       1 2 1        1
      21             11   1    11221  1      1
    1 2      1   1  1     11     11   1   1
  11  2       1   2       11 11112     1     1   1
 1  1 11       111 2  1 1  1    111    1       1
  2    1    1      1      11  1111   1 1        11
  12  1                                  1
    1          1  11             11  1 1  1 11 1 1
       1     2   113  1               1
  1  111       111   1 2   1    11  1  1    11 1
   1 11        1  2              1           1
   11 21  1 1  1                  1     2  1     1
12  1  1 41 2  211 1   1  1    1         1  1
  221        1 11 11  11           1  11 1       1
  312    1                1        11  1     1
1  3     1  1    122   1  1   1   1   1     1
1 31  41     1     2   1      1  1111
  12212        1   1    1     1 12
   21 23     1 1 1 1     1        21      1  1
  6 3 1    111       1  11 1    2 1   1 1   2
   11       1  1   1        11              1   1
  211          2   2    1 1   1
  211 11    2  1 11       1   1111   11
 12   11 1  2 11  2111 1  1    12 1              1
 21         1  111        1  1 1      1     1  1
   1        11 211    111 1   1  112 11  1       1
   1  1     1  2       11     211 21  1
   21  1    1  1   2      1   111  11 1
  1         1  11111            1    1  1
  212             1              1  2
        1   1  2  11 11   1    1 1111111 2
  2   11    11     1  1          1 111       1 1
 1 11          1  111         1    111     111
  1111  111    1   1  1     1      112      11
               1     1 1 1      22  211 22 111
      1        1 1 1               2121 313 21
  11 13 1          2  11            111 22211 11
  11  2        1   2            1   11       1
   11 3        1 15             11  21     1  1
1 111 11    1                11 11         1
      1                    2      1   1     11 2
1  2           1  21 2            1111      1 1  1
1 12     1        1   11  1   1   1 21   1     1
 11   12  1   1111112                1     211  1
   2  1   1  1 1     11       1  11 1      1112 1
   21 1         121  1 1      1   1   1  22 21  1
1     2        1  4  32 1    1   2    2 1 1      1
1 16  1      1     1    11 13  1 11   111   1 1 11
1 11  1    1      11 1        1  1        1     1
  1            3   1             1 1       1 2   1
 6 2           31      1  2 11 1         3111221 1
1E24  3  12  1 21 1         1 3  1 1     3 1 11 1
 Q 1 16 1 2  1  1    1               11 11  1 1
 U31  1      3 7  1              1    2  11    1
2J1   31 3 111  11 1 12       2 12  2 1 2111 11211
 51            1  1           1 1   1   121   1 1
  14   1   113   2  111        11   1   1111111
 1 3  1   1    1       11 1        1  1 12 112  1
 1 4      1  1 1  11  2       11  1   1 111 11
   4  1 1  1 11   111         12 1    1  1211 1
   1        1    2 1               11    1   2 11
 1 1  1        11  1      1    1 1      3 2
   1      1       14    11        1 1     3 1 21 1
1  1  1        2    1   1 1       11   11112  1 1
   11 2    1 1 3   1    1    1   1 11   2 11    1
1  1           1 1   1    11  1  1111 2     11
2     3      1 3 11              1111   11   11
2  3  4 1  1   1        1 1   1     1   1 2 111 1
      1           11            1  112    1   11
     12 1 1       111     1 21 2   111     1   211
 2    5    1 1  1     2      1    1 11  1 2 1    1
 1 2  1        1   1   1    1  1  112     1 1
   1  1     1         11       11  1 11
   1      1    2              2  1 12     2  2 1
2  3  1    2   1 1  1      11     11111    1

Licensing

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I, the copyright holder of this work, hereby publish it under the following license:
w:en:Creative Commons
attribution share alike
This file is licensed under the Creative Commons Attribution-Share Alike 4.0 International license.
You are free:
  • to share – to copy, distribute and transmit the work
  • to remix – to adapt the work
Under the following conditions:
  • attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
  • share alike – If you remix, transform, or build upon the material, you must distribute your contributions under the same or compatible license as the original.

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Date/TimeThumbnailDimensionsUserComment
current04:06, 7 October 2017Thumbnail for version as of 04:06, 7 October 2017450 × 538 (48 KB)Omegatron (talk | contribs)User created page with UploadWizard

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