Radio meteor detection system



2015-02

2015-01

2014-12 Note the geminid meteor shower (peak 12/14/2014)

Last strong echo

Listen (in testing phase)
LastStrongEcho.wav


Frequency (audio Hz from receiver) by time


Frequency by time summary


Daily totals

About Radio Meteor Detection

Radio meteor detection can be done by tuning in a video signal of a VHF TV station which you normally do not get a signal on and is within a couple hundred miles. The reason this works is when meteors enter the earth's atmosphere the heat and the pressure ionizes the air. The ionized air works as a radio mirror for a short time. The radio signal of the TV station bounces off of the ionized trail and you can hear the station for a very short duration.

These charts were made by monitoring the pilot frequency of a TV station using CW mode. The audio output is ran to the sound input of a computer and the sound is analyzed and detections are logged using Spectrum Laboratory https://www.qsl.net/dl4yhf/spectra1.html

Detecting meteors after the digital TV transition

Digital television transmitions contain a carrier frequency that is suitable for detecting meteors. With my original station I was detecting meteors using the ATSC pilot frequency of digital TV station channel 6 (82.31 Mhz). I had to tune down a little to 82.3094 Mhz but your exact tuning may vary. With the radio turned to 82.3094 Mhz in CW mode I get an audio signal of about 850 Hz when a meteor is detected.
What a typical detection sounds like
Below is a link to an audio file (wav) containing what a typical detection sounds like along with some background noise. Best to right click and choose "save as" and then play in your preferred audio player.
Typical detection

ATSC pilot frequencies

ChannelPilot Frequency (Mhz)
254.31
360.31
466.31
576.31
682.31
7174.31
8180.31
9186.31
10192.31
11198.31
12204.31
13210.31
14470.31
15476.31
16482.31
17488.31
18494.31
19500.31
20506.31
21512.31
22518.31
23524.31
24530.31
25536.31
26542.31
27548.31
28554.31
29560.31
30566.31
31572.31
32578.31
33584.31
34590.31
35596.31
36602.31
37608.31
38614.31
39620.31
40626.31
41632.31
42638.31
43644.31
44650.31
45656.31
46662.31
47668.31
48674.31
49680.31
50686.31
51692.31
52698.31
53704.31
54710.31
55716.31
56722.31
57728.31
58734.31
59740.31
60746.31
61752.31
62758.31
63764.31
64770.31
65776.31
66782.31
67788.31
68794.31
69800.31
70806.31
71812.31
72818.31
73824.31
74830.31
75836.31
76842.31
77848.31
78854.31
79860.31
80866.31
81872.31
82878.31
83884.31


Meteor Rates and Why Meteor Showers Happen Regularly

The reason we experience meteor showers is that as the earth orbits around the sun it passes through areas that are more dense with debris. These areas are often near the orbits of comets and asteroids. For example, each spring during the Eta Aquarid meteor shower Earth passes an area with debris from Halley's comet.

The peak time for meteors at a given location tends to be around 6am local time no matter where you are. This is due to the fact that you are standing on the leading edge of Earth's rotation as the below illustration shows.



Log
2019-09-30
Strong QRM has been preventing reception across most radio bands again over the last few days severely impacting performance of the radio meteor detection system
2019-08-13
Strong QRM was preventing reception across most bands. Possibly related to nearby electrical line work being done
2019-07-24
Station is back up and working. There were 2 problems. A cable end had corroded and was no longer making a connection. Upon fixing that I was still getting very weak signals. Ultimately it turned out that the pre-amp I was using had also failed.
2019-07-23
The station remains down due to an antenna/cable issue. Hopefully it will be back up soon.
2019-07-22
There was a bad connection. Re-did BNC connector on main antenna cable. Still testing
2019-07-21
System is not working. Possible antenna problem. Possibly another cause
2019-07-20
Temporary radio propagation conditions have affected the ability to detect meteors intermittently lately.
2019-07-09
Changed back to Kenwood TS-2000 on 54.3094 Mhz, the TH-F6 was experiencing frequency drift
2019-07-08
Changed radio to Kenwood TH-F6 on 54.3097 Mhz as a test at 3pm CDT (note: was getting solid signal at the time, need radio conditions to improve to fully test)
2019-01-29
Re-tuned to 54.3094
2018-10-04
Re-tuned to 54.30945 (testing)
2018-10-03
Re-tuned to 54.3096 (was 54.3095)
2018-09-05
Re-tuned to 54.3095 (was 54.30954)
2018-09-03
Changed to new station on 54.30954 Mhz using Kenwood TS-2000 on quadrifilar helix antenna
2018-09-01
Changed threshold to 16 (was 17)
2018-08-31
Changed threshold to 17 (was 18)
2018-08-30
Changed range to 820-1050hz (was 870-1100hz)
2018-08-29
Re-tuned to 82.3096 Mhz (was 82.3095 Mhz)
2018-08-26
Changed range to 870-1100hz (was 770-1000hz)
2017-01-13
Re-tunred to 82.3095 Mhz
2016-09-04
Changed beginning of frequency range for trigger actions to 860 (was 600) to avoid auroral propagation from setting it off
2015-11-21
Re-tunred to 82.3095 Mhz as a test, then tuned back to 82.3094 Mhz
2015-03-17
Auroral propagation caused some false detections. There was a severe geomagnetic storm where the KP index reached 8 during the peak. It was the strongest geomagnetic storm of this solar cycle so far. Chart.
2015-02-01
Removed data for 5 hours. Possible sporadic-E
2015-01-07
Now running on a different computer
2014-12-26
Now running with RMOB conversion routine and submitting results to the radio meteor observers page http://www.rmob.org/livedata/main.php

2014-12-13
Re-tuned receiver to 82.3094 Mhz

2014-11-13
Some people may say I have the %#!@ touch with sound cards. It may be true. Yesterday the input went bad on the sound card I was using for the meteor logger. It is now running again now on a turtle beach USB sound card (an Amigo II) that I had on hand. Turtle beach to the rescue. If you have the %#!@ touch with sound cards like I do, you may want to keep a couple of these on hand. ;)

2014-10-21
As Murphy's law would indicate, on 2014-10-21 (Peak of Orionid meteor shower) the computer that has been running the meteor logger flawlessly for over 2 months unexpectedly rebooted while I was sleeping and so I lost a good chunk of data. (~7am-~11:40am)
Visually I saw 27 meteors at a rate close to 3 times normal meteor rates from my locaton while the logger while running does not show a significantly higher rate. It is possible that most of the meteors associated with this shower were not strong enough to make non specular detections with my current setup.

Various Charts

Frequency and Time



Frequency and Time - Lyrid Meteor Shower


Amplitude and Frequency
Note the gap between 775 and 895 hz, that is part of the airplane filter



Perseid Meteor shower 8/12/2014

Amplitude and Frequency

Frequency and time


Archive

Visually witnessed detected meteor

Just after 1 AM on August 31, 2014 a friend and I witnessed a bright meteor in the West, moving East to West. We checked the meteor logger and the meteor showed on the FFT and the meteor was detected.
Part of FFT showing the meteor echo (red line on lower right of image)


Frequency chart showing the meteor detection


Data of actual detection (DateTime, Frequency, Amplitude)
08-31-2014 01:00:12,1010.3,-63.5
08-31-2014 01:00:12,1010.3,-63
08-31-2014 01:00:13,1013.7,-64.3
08-31-2014 01:00:13,1013.1,-65.1
08-31-2014 01:00:14,1013,-62.2
08-31-2014 01:00:14,1013,-64
08-31-2014 01:00:14,1012.1,-66.1
08-31-2014 01:00:15,1008.4,-64.6
08-31-2014 01:00:15,1008.4,-64.2
08-31-2014 01:00:15,1008.2,-65.8



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