We'll focus on the implementation of a amateur passive reception station for counting meteors. P>
It is not this is a
Installation "amateur" because we are not interested in
emitting radio waves, but only upon receipt. In addition, this
reception is only oriented counting meteors, not
Once the proper settings found the sound of the receiver is
useless or even rude to me and it is cut continuously.
Our goal is ASTRONOMICAL.
Amateurs interested in it will have a huge
advantage over "astronomers", they have mastered the technical part! p>
Which beacons listen ?
- Europe : listening Graves Radar
- Northwest Europe : listening VVS and BRAMS beacon
- USA-South America-Russia-Asia : listening TV band I beacons
- Japan : listening dedicated beacons in japan
- All in the world, but it is most difficult : listening FM broadcast
Equipment choices constraints
Given that we learned in the "Theory page" we know better "observing" is in the frequency range from 28 to 200 Mhz. p>
We will refine this choice.
We must find a frequency band or there
suffisement powerful remote transmitters scattered preferences
isotropic way (almost) emitting 24h/24 and where it is possible
observed with a maximum chance of having echoes.
A quick "study" of the frequency spectrum from 28 to 200MHz
shows us that there are two areas where you are most likely to gather
these conditions. p>
Which beacons listen ?
The very useful band is :
TV transmitter in VHF band I between
48 to 70Mhz and 50 Mhz amateur radio area.
In USA, South America, Asia and Russia many TV transmitter in VHF band I is running.
It is a good choice for these countries
In Western Europe the TV transmitter band I is cut from 2011...
In Western Europe the best choice in now the Graves radar.
is a French radar-based space surveillance system, akin to the American NAVSPASUR. Using radar measurements, the French Air Force is able to spot satellites orbiting the Earth and determine their orbit.
The frequency is 143.05 Mhz, slightly high, but stronger power trasmitter compensates the high frequency.
More info see Wikipedia Graves radar and this document from the Britsh Astronomical Society Detection_of_meteors_by_RADAR.pdf
In northwest Europe, in Belgium, Netherland, North of France, Southeast of UK, Northwest of Germany, 2 small power beacons exist, specially dedicated for listening meteor echoes.
The VVS beacon from Vereniging voor Sterrenkunde (VVS), Belgium at 49.990 Mhz for 50W power. See SAO/NASA ADS document
and BRAMS (Belgian RAdio Meteor Stations) from the Belgian Institute for Space Aeronomy.
The frequency is 49.97 Mhz and the power is 150W. See BRAMS
The problem for all other countries in Europe is the small power of these transmitter.
For sample, for me,I live in south of France at around 1000Km from the transmitter the power back from meteor is too faint.
In Japan some beacons dedicated for meteor listening exist from a long time.
the MU radar (46.5 MHz) of Kyoto University (MURO) and Ham(TX:53.750 MHz, (JA9YDB), Ham Club of Fukui National College of Technology (Mr. Maegawa) and 50.017 MHz, JA6YBR, Ham Club of Miyazaki University, operated by Mr. Kinoshita) radio (HRO)
Another useful frequency band is FM broadcast.
But, all around the world all channel of this band is occuped. For listening the meteor is necessary to find an free channel...
In Western Europe is unavailable to find a free channel !
a) Radio hardware :
The antenna support mat.
The descent of coaxial cable to the receiver and plugs
necessary for the interconnection cable between antenna and receiver.
A receiver capable of covering the range of frequencies that are expected to observe.
b) Computer hardware :
From old PIII 800Mhz to the most, but the most is not necessary !
Avoid Mac (sorry) because there is no special software !
The operating system can be Windows 98 to XP (avoid Vista-W7-W8) or Linux using Wine emulator.
C) The softwares :
Usualy an audio spectrum software specializes in counting meteors, like HROFFT or SPECTRUM LAB, but some observer use specialised interface.
Colorgramme Lab for the visualisation, count and data transfer to www.rmob.org live data web site
Possibly a software interface with your receiver if it is controlled by the PC.
The choice of equipment depends on the radio frequency range or you want to observe.
For FM an TUNER is sufficient !
For the band I TV is more complicated. Not using a television that does not work.
It seeks to record changes in the reception of
video carrier distant TV stations, and this with a band
Bandwidth extremely selective to avoid that interferrences
not lacking in these frequencies.
As an indication that the receiver must be at least
capable of filtering 6KHz USB or LSB see less if possible.
I use mine with only 2.8Khz bandwidth in upper side band (USB), a SSB form. See WIKIPEDIA for more information if you
know what it is : Wikipedia SSB
Receivers capable of these performances are usually specialized and therefore expensive option ...
In addition we must "reserve" the opportunity to explore a
Much of frequencies that interest us as to find a
ideal setting often requires several test frequencies sometimes
distant from one another.
How to choice ?
Find an observer close to your location on www.rmob.org and look its configuration, receiver-antenna-frequency.