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"Thank you so much for visiting our class on
Friday! The kids loved it...they thought it was pretty cool to meet a
"real" Astronomer! Thanks again, Janine"
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Updated 14 Mar 2011
DC
Here are the results of our test of FM radio meteor detection for the
spectacular Leonid Shower of November 2001. On this page we offer:
 | A picture of the reflection geometry |
| A description of the equipment we used |
| Graphs showing the meteor counts for the morning of November 18 |
| Audio files of a meteor reflection |
Reflection Geometry
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We are located in Edmonton, Alberta. Our
equipment was tuned to a radio station in Calgary, Alberta, approximately
300 km almost due south.
The meteor (white streak in picture) travels at a tangent to an ellipse
(yellow) with Edmonton and Calgary at its foci.
Radio signals (red) that would not have otherwise reached Edmonton were
reflected off the ionization trails of meteors between the two cities. |
Equipment
- A 6 element Yagi antenna was connected via coaxial cable to a digitally
tuned FM stereo receiver tuned to 92.1 MHz, a Calgary radio station.
- An earphone jack in the receiver was connected to the Line In jack on the
sound card on a Pentium 1 - 166 MHz computer. The computer had Radio Sky
Pipe (free) data logging software installed on it. This software is
available from Jim Sky at www.radiosky.com.
- These first two steps make up the basic equipment configuration you need
to observe meteors with an FM radio.
- To record the sound of the Calgary radio signals reflected off meteors,
the FM receiver Audio Out was connected to the Audio In on a VCR.
- A television was connected to the cable TV in the house and tuned to the
local cable TV channel with time and date showing.
- The Video Out from the TV was connected to the Video In on the VCR.
- The VCR records the sound from the radio and the video time stamp from the
cable service. This allows the reflected radio station signals to be
recorded on VCR tape alongside the video signal allowing you to know when
the signal was detected and to hear the signal all at once.
Graphs of Results
These last three strip charts of data collected with the Radio Sky Pipe
software clearly shows the increase in the number of meteors detected over three
days during the hours between midnight and 6 am leading up to and including (the
last strip chart) the peak activity night.
This graph shows the tally of meteor counts from the peak night.
Hear and See the Results
| Push this button to hear what a meteor reflection sounds
like. You can hear the station identify its frequency as 92.1 in this
recording.
This
graph shows the sudden rise in signal strength when you hear the words and
music in the recording. |
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