Wednesday, January 9, 2013

Detecting meteors by radio reflection in 2013

Some years ago I made meteor observations using the low VHF band TV transmitters around here with great success. Even with nearby transmitters I was able to see reflections from airplanes. Analyzing those doppler reflections some interesting info can be obtained. But with time, all those TV transmitters moved to digital at UHF frequencies so nothing can be heard now. I tried some amateur beacons but their low power and modulation are not adequate for this kind of observations.

From time to time as propagation permits I can hear some TV carriers around the usual frequencies: 48.250, 53.750 and 55.250 MHz but no meteor or plane reflections: They are too far away and their signals reach my antenna via multi hop sporadic E or F2 so they are not useful for meteor detection.

So, what are the most suitable signals for this kind of job right now?

For meteor detection the most reliable signal here in Europe is Graves radar. Its signal is a continuous carrier at 143.050 MHz and it is so strong it can be received with almost any system: I was able to hear meteor reflections from Graves using a FT-817 and its rubber duck antenna. I receive them easily with my vertical antenna and reflections are very strong, peaking over S9 many times.

A Quadrantid head and trail meteor echo received
from Graves at 14:49:23 UTC on January 3, 2012

To receive the Graves radar just tune your receiver to 143.049 MHz USB mode and if your antenna is directional, point it to JN27 square. The Graves signal will appear at the speaker as a 1 kHz tone.

Graves radar signal is very useful for amateurs. If you live near it, you can use it to detect airplanes, meteors at larger distances or if you are completely out of its range (about 2000 - 2200 km) you can receive its signal reflected on satellites, the ISS or even the moon. Take a look at for a great example about Graves usage.

For airplane detection, if your are far away from Graves radar your best bet is to use VOR signals. VOR transmitters use the frequencies between 108 and 118 MHz and many of them are high power so detection is easy. As a bonus, there are several VOR transmitters around the world, so it is sure you will have some dozens around you.

Maybe you are wondering now why to detect airplanes if the goal is to detect meteors. Airplanes are a perfect object of study, they move much slower than a meteor, and you can know its precise position in real time, so you can correlate doppler received values with trajectories, velocities, etc. From this, moving to meteor study is just one step forward.


  1. I remember aircraft reflections on 21610 kHz by REE, the Spanish short wave broadcasting station. I never did anything useful with them :-(

  2. and where to point if we are behind the radar ?