Post by Al Degutis on May 6, 2005 12:21:33 GMT -6
Wish I had seen this sooner so I'd have time to set up for it. It would have been great to audibly observe the Eta Aquarids after sunrise or during todays cloudy morning.
From www.jas.org.jo/radio.html
How it Works ?
When a meteoroid enters the atmosphere, the particle will completely ionize its trail at an altitude that ranges between 120 km and 80 km, and the ionized trails are capable of reflecting radio signals from terrestrial stations, which include those broadcast by commercial FM and TV stations. The advantage of of this kind of observation that it can be done in daylight and during cloudy or rainy weather ! Also the moon's light is no more annoying when observing meteors by radio. Radio detection rates of meteors tend to be higher than visual observation rates.
The easiest way to observe meteors by radio is to use commercial FM radio (preferable digital), and attach it to an antenna (preferable FM Yagi antenna), then try to find an empty frequency from 87.5-108.0 MHz, where you do not hear any kind of music or talking, and is being used by a distant transmitter (mostly a distant FM radio station) about 300-2000 km away from your location of observation (preferably 500-800 km). It is better to choose a station that transmits over 30 kilowatts, and point the antenna towards the station. Now, all what you hear is a continuous static, and when a meteor passes and if its position is suitable then it will reflect the waves of the distant station and you will hear it, the period varies from 0.1 second to several seconds or even minutes (mostly on the order of 0.25 second). They are small segments of what is being transmitted. They sound like bumps, thumps and chirps. The longer signals are recognizable pieces of music or talking. To distinguish the signals reflected from a meteor than others such as aeroplanes, the signals reflected from a meteor is very sudden, mostly loud and clear, and end gradually.
From www.jas.org.jo/radio.html
How it Works ?
When a meteoroid enters the atmosphere, the particle will completely ionize its trail at an altitude that ranges between 120 km and 80 km, and the ionized trails are capable of reflecting radio signals from terrestrial stations, which include those broadcast by commercial FM and TV stations. The advantage of of this kind of observation that it can be done in daylight and during cloudy or rainy weather ! Also the moon's light is no more annoying when observing meteors by radio. Radio detection rates of meteors tend to be higher than visual observation rates.
The easiest way to observe meteors by radio is to use commercial FM radio (preferable digital), and attach it to an antenna (preferable FM Yagi antenna), then try to find an empty frequency from 87.5-108.0 MHz, where you do not hear any kind of music or talking, and is being used by a distant transmitter (mostly a distant FM radio station) about 300-2000 km away from your location of observation (preferably 500-800 km). It is better to choose a station that transmits over 30 kilowatts, and point the antenna towards the station. Now, all what you hear is a continuous static, and when a meteor passes and if its position is suitable then it will reflect the waves of the distant station and you will hear it, the period varies from 0.1 second to several seconds or even minutes (mostly on the order of 0.25 second). They are small segments of what is being transmitted. They sound like bumps, thumps and chirps. The longer signals are recognizable pieces of music or talking. To distinguish the signals reflected from a meteor than others such as aeroplanes, the signals reflected from a meteor is very sudden, mostly loud and clear, and end gradually.
