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Meteor scatter (MS) is the reflection of radio signals from the ionised trails from  Meteors (Iron Rocks) burning up in the upper atmosphere. This effect can be used by radio amateurs to make contacts at distances of up to around 2,200km. Meteors burn up in the atmosphere at a height of between 90-105km. The ionised meteorite trail will reflect VHF radio signals, which would otherwise travel straight into Space. 

Meteor Scatter radio contacts rely on multiple meteors to reflect small parts of each message over a period of time, usually around 20 minutes, but sometimes up to 1 hour. The mostly metallic (iron) meteors burn up in the atmosphere and leave an ionised trail of particles, which VHF radio signals can bounce off, for any time period from 100 milliseconds to over 2 minutes. The frequent time for reflections  is often around 250 milliseconds or just a quarter of a second!

You haven't time to speak normally, so you can use a series of audio tones to represent each letter of the alphabet and play this through your radio using a computer soundcard. You speed up the tones so that your short message instead of lasting perhaps 20 seconds, is transmitted in under 0.25 seconds, repeatedly over and over again.

Imagine a spy radio 'burst transmitter' sending a secret Morse Code message at hundreds of letters per minute very, very quickly to avoid detection and direction finding by the enemy! The techniques used for Meteor Scatter communication speeds are quite similar.

The receiving station listens and when a meteor is in just the right place he/she will hear your signal and then they slow your message down again to read it, using their computer soundcard and WSJT software. You take it in turns to transmit and receive in set periods of every 30 seconds. Over 20 minutes, on average, the entire message is transferred in both directions to complete the contact. In this time maybe 4-6 meteors will occur.

Meteors may come at any time, but sometimes they come in showers, which can be predicted. During showers there are more meteors than usual and QSOs (contacts) are easier to make. Most work on 144 MHz is done during Meteor Showers. A MS trail reflects 50MHz for longer time than 144MHz, so it is easier to work MS on 50MHz. Actually you do not need to wait for a MS shower at all to make QSOs, you can arrange skeds via the ON4KST 50/70/144/432 MHz online Chat.

Meteor Scatter signals sound like brief enhancements of the signal you are listening for. Out of the noise pops your QSO partner at 59+ for mostly less than a second, but then he fades fast away again. Sometimes bursts are many seconds long and you may be lucky to make a QSO in one burst. But as ever on VHF you have to be fast..

 

 

If you are new to Meteor scatter and want to try to receive pings/reflections to test your equipment works, then I would recommend the following frequencies:

For many years I used to monitor the extremely powerful Band 1 VHF TV stations analogue carriers on 48.250 MHz CW to test my MS receiving capabilities, with a 250 KW transmitter in Spain, IN70 locator square, being particularly useful before it closed down and was replaced with UHF Digital TV transmitters in 2010.

 

All analogue TV stations in the Czech Republic closed down on 30th June 2012. Portugal ceased on 4th May 2012. For a list of analogue TV closures by Country please follow this link for Digital Television Transitions 

It appears that time is rapidly running out for Band 1 TV video carriers audible via Meteor Scatter reflections here in Northern England and few options remain primarily in Ukraine, Russia and Iceland. The ideal distance for such transmitters is not less than 300 km and not further than 1500 km away from the receiving station, although a maximum working distance can extend as far as 2,300 km but with much weaker reflected signal strengths.

Radio Meteor Scatter detection sources for Northern England
Carrier Frequency or USB dial (MHz)	Power	Location	Distance from IO84	Remarks	Results	Last heard
32.550	12 kW	JP89 Norway	1842 km	SkiYMET, Andenes Meteor Radar, Institute Atmospheric Physics, over ideal 1500 km distance & good power. At solar maximum frequencies between 30-35 MHz can be negatively impacted for MS working. N.B. Operating in pulsed mode, not CW carrier (Thanks Toralf DJ8MS for info)	Tested May 2012, nil heard
32.550	12 kW	JO64 Germany	1017 km	Juliusruh Meteor Radar, Institute Atmospheric Physics, good distance & power. At solar maximum frequencies between 30-35 MHz can be negatively impacted for MS working. N.B. Operating in pulsed mode, not CW carrier (Thanks Toralf DJ8MS for info) .	Tested May 2012, nil heard
36.200	12 kW?	JO61 Germany	1110 km	Collm Meteor Radar, near Leipzig, good distance & power.  N.B. Operating in pulsed mode, not CW carrier (Thanks Toralf DJ8MS for info) .
39.025-39.175	10 W or 100 W versions	UK Locations unknown	? km	UK Meteor Burst Communications (MBC) 7 x 25 kHz channels. Full locations unknown, one company operates master station at Newbury, Berkshire. There are now 5 master stations. May be Mobile Meteor Burst Stations (MMBS) and only transmit once per hour. See reference document. European harmonised Meteor burst frequency allocation is 39-39.2 MHz.
46.400	170 kW	UK Locations unknown	? km	UK Meteor Burst Communications (MBC) .	Tested September 2012, nil heard
46.500	8-160 kW	IO72XK Wales	263 km	NERC MST Weather Radar Facility. Below recommended minimum 300km distance. Pulsed signal not CW apparently. .	Tested May & September 2012, nil heard
46.950	? kW	UK Locations unknown, suggestions possibly Southern England & IO91	373 km (if IO91)	UK Meteor Burst Communications (MBC) Possible MAIN frequency? .	Tested September 2012, two extremely weak pings and missed Fireball over UK on 21.09.2012 completely!	September 2012
46.975	? kW	UK Locations unknown	? km	UK Meteor Burst Communications (MBC) .	Tested September 2012, nil heard
49.738844 USB	40 kW	KN29 Ukraine	1970 km	TV Carrier Lviv R1, until 2015, over ideal 1500 km distance	Heard via Sporadic-Es May 2013. Very distinctive wobbly carrier seen using SpectrumLab	May 2013 on Wellbrook 1530+ Loop
49.739.66	150 kW	JO70 Czech Republic	1285 km	TV Carrier Prague R1, until June 2012, good distance and power	Closed down June 2012
49.749.83	17 kW	KN68 Ukraine	2536 km	TV Carrier Krivy Rig R1, until 2015, over maximum workable 2,300 km distance for me	Not workable too far away for me	Not workable too far away for me
49.749.98 USB	? kW	K033 Belarus	1934 km	TV Carrier Minsk, Belarus R1, over ideal 1500 km distance	Signal on this frequency heard via Es on 30.04.2012. Testing in September 2012 has found a few daily Meteor pings.	September 2012
49.750 CW (49.749335 USB)	? kW	KP50 Russia	2090 km	TV Carrier St.Petersburg, Russia R1, over ideal 1500 km distance	Testing in September 2012 has found a few daily Meteor pings and strong via Sporadic-Es in May 2013.	May 2013 on Wellbrook 1530+ Loop
49.760.4	100 kW	JN99 Czech Republic	1590 km	TV Carrier Ostrava R1, just over 1500 km distance, good power	Closed down early in November 2011. Thanks Martin G4FUI for the update
49.970 (49.96917 USB)	150 W	JO20 Belgium	702 km	BRAMS Meteor Beacon, Balise Dourbes, Belgium dedicated MS beacon, but low power, very good distance	Very few weak pings detected so far	2012
49.990 CW 49.98918 USB	50 W	JO10 Belgium	607 km	VVS OT1KZG Meteor Beacon, Ypres, Belgium dedicated MS beacon, but low power, very good distance	Some frequent, but weak pings detected. Stronger and more frequent than Balise Dourbes transmitter though	2012
53.500	12 kW	JO64 Germany	1017 km	Juliusruh Meteor Radar, Institute Atmospheric Physics, good distance & power. N.B. Operating in pulsed mode, not CW carrier (Thanks Toralf DJ8MS for info)	Tested May 2012, nil heard
53.500	4.5-90 kW	JO54 Germany	889 km	OSWIN VHF Radar, good distance and power varies. N.B. Has not been operating in Meteor Scatter mode since 2009 (Thanks Toralf DJ8MS for info)
53.500	2.4-60 kW	JQ78 Svalbard	2717 km	SOUSY SSR VHF Radar, over maximum workable 2,300 km distance	Not workable too far away	Not workable too far away
53.500	1.8-36 kW	JP88 Norway	1842 km	ALWIN VHF Wind Radar, good distance and power varies. Pulsed signal, not continuous carrier wave. Can sometimes be used to measure Meteor activity when the site operator wishes, but not main priority.	Tested May 2012, nil heard
55.250.071	90 kW	HP85 Iceland	1628 km	RUV TV Carrier E3 Stykkisholmur until 2013, over ideal 1500 km distance, excellent power, not known if 24H or closes down at midnight.
55.250 CW 55.24920 USB	60 kW	IN50 Portugal	1640 km	TV Carrier E3 Lousa, over ideal 1500 km distance, excellent power. Due to shutdown permanently on 26th April 2012, followed by a final week in TV test card mode. My last detected Meteor ping was at 0920z on Friday 4th May 2012.	Closed down 4th May 2012
59.257175 USB	7 kW	KN18 Ukraine	1897 km	TV Carrier Uzghorrod until 2015, over ideal 1500 km distance, power less than most TV stations	Heard via Sporadic-Es May 2013	May 2013 on Wellbrook 1530+ loop
59.297.8	150 kW	JN78 Czech Republic	1341 km	TV Carrier Ceske R2, until June 2012, good distance and power	Closed down
62.251.325	300 kW	HP83 Iceland	1051 km	RUV TV Carrier E4 Skalafell until 2013, good distance, excellent power, but may close down at midnight until 0800.
143.050	<767 kW	JN27SI France	(1000 km) 1250 km	GRAVES Military Space Radar system, believed excellent power, fairly good distance, but high frequency with far fewer reflections detectable compared to 50 MHz. Note distance is not to transmitter site itself but to area of Southern France 250 km further South where Ionosphere is illuminated by the Radar at 100 km altitude and reflections detected. However, in theory this is detection via Backscatter and ideally Forward scatter is much preferred for MS work.	Possible few weak reflections detected	2012

N.B. If monitoring any of the above CW carrier frequencies using SpectrumLab or similar software, you will most likely need to be in USB mode and therefore around 800 Hz lower in displayed frequency than quoted i.e. 55.250.0 MHz CW carrier = 55.249.2 MHz in USB on your radio display, then look for the signal at around the 800-1000 Hz point on the software screen.

 

 

An alternative high power transmitter exists, but is much more difficult to use.

 

 

143.050 MHz CW - This is the carrier frequency of the French GRAVES space surveillance radar system and will provide pings from both meteors as well as satellites! Maidenhead Locator Square JN27SI near the City of Dijon and the border with Switzerland. (Red dot on map indicates transmitter location on former airfield)

 

 

There are 4 Phased Array antennas on 143.050 MHz CW situated on a disused Airfield. The four transmitted beam lobes are designed to overlap and cover a 180 degree arc of Sky, at an elevation of 25 degrees, in a Southerly direction towards the Mediterranean Sea.

 

Preliminary experimental results using only an indoor 144MHz 1/2 wave colinear on 143.050 MHz CW have produced what I think may be Meteor Scatter reflections or the ping could could be from a satellite! In the screen grab below there is a distinct vertical ping shown in a bright yellow colour just before 0625 UTC on 24th March 2012.

 

I am also experimenting in 2012 to see if some of the dedicated Institute for Atmospheric Physics (IAP) high power VHF transmitters for Meteor Scatter detection are audible here in the North of the UK. There are stations located in Andenes, Norway on 32.550 MHz  running 12 kW and another station in Juliusruh in Northern Germany on 32.550 and 53.5 MHz at 12kW.

 

 

 

 

Here below are my first attempts at automatically uploading my latest captured Radio detected Meteor Scatter images. Inspiration entirely drawn from Andy G7IZU and his excellent web guide on how to do this. I am using DL4YHF SpectrumLab software to capture the images and AutoFTP Pro to send them to this website automatically every 10 minutes whilst the system is active. Technically I suppose this is Radio Astronomy. If there are no meteors then this image will be mostly blank.

 

Meteor Pings captured in the above image (if detected) should also show up on the live Plotter image below, where they exceed -50 dB signal level as high green coloured peaks and should correspond with the 3D image below that. My audio input noise level runs at around -65 dB. An example Plotter image showing the green spike of a detected Meteor ping at -35 dB signal level, is shown below the live image.

 

 

 

 

 

And if there is something 'special' to see then, in theory, an Alert image should be shown below! This is still very much in test mode.

 

 

 

 

I have decided to experiment using a FUNcube Dongle Pro, which in theory can be used from 51.5 MHz - 1700 MHz (Rated from 64 MHz - 1700 MHz) all mode including SSB to turn my laptop PC into a dedicated radio receiver. I will use with SDR-Radio.com software for frequency control and SpectrumLab to analyse Meteor Scatter results. This will also permit me to experiment with the GRAVES Space Radar on 143.050 MHz too.

 

 

First impression of the FUNcube Dongler Pro was that it requires considerable Radio and computer knowledge to setup properly. Took a little while to find the information online how to update the latest firmware (required for all features and software compatibility) and set it up for proper use. Tried initially SDR-Radio.com software as my preferred front end, as it is so very comprehensive, however I ran into a common problem of listening to a local Band II FM Broadcast Radio station on 92.5 MHz FM and the audio being very distorted.

Several hours later, by trial and error, I have tried the alternative HDSDR software front end and have little to no audio distortion when using 96000 Hz in and 96000 Hz out audio settings via the soundcard. Had intended to try again with SDR-Radio.com software on frequencies other than Broadcast FM which shouldn't cause overloading or exceed the audio bandwidth specification of the dongle.

I have ceased to use the FUNcube Dongle completely, preferring instead to use my other radios.

 

 

 

 

When transmitting signals within the Amateur Radio VHF bands you should prepare yourself to make the QSO in small bits of mostly a few seconds. There is a procedure for MS-QSOs agreed on in IARU Region 1. If we all follow it, the QSOs are much easier.

PLEASE NOTE: Meteor Scatter guidelines suggest that if possible, Northbound and Westbound transmissions should be made in the 1st period and Southbound and Eastbound transmissions should be made in the 2nd period.

This will avoid you causing QRM by transmitting when other local amateurs are listening! This guide is often ignored by stations who are unaware of it and results in havoc, with you trying to listen for weak signals at the same time that a nearby strong station is transmitting. (However for stations in central Europe it can be difficult to comply because different stations in the same Country may be working to the West and the East at the same time, so you should arrange a scheduled QSO on a frequency away from 50.230 MHz or 144.370 MHz in that case).

METEOR SCATTER REPORTING SYSTEM

 

 

 

 

 

   

I used to record radio detected Meteor Shower ping activity on 55.250 MHz over several years using the excellent and reliable data from Dave Swan, however I have had to stop due to the primary transmitter in Portugal closing down. The table below shows the recorded data and is useful for working out the best dates for MS propagation, albeit random meteors occur at any time.

UK Radio Meteor analysis shows that the best times for working random Meteor Scatter is between 0000-1300hrs with few meteors outside these times, obviously Meteor Shower peak times do differ from this general rule. I have found operating FSK441 for random Meteor Scatter during the afternoon and early evening has not been as good, but DX can be worked with perseverance. Full Meteor Shower list can be found here. An excellent website dedicated to the study of live Meteor reflections is that of G7IZU.

Below - Dave Swan's (G1BLO) radio meteor reflections at 55.250 MHz and live observation histogram at 62.1927 MHz as received in the UK, a very good indicator of meteor activity. The Geminids meteor shower peak on 14th December 2003 can be clearly seen at 0400hrs UTC on the December 2003 chart shown below.

 

EUROPEAN METEOR SCATTER FREQUENCIES

I have found that the following WSJT modes and frequencies are in common use and would appear not to conflict with other band users 

 

When calling CQ with FSK441A (WSJT) on 144.370 MHz most amateurs have adopted the method of sending 'CQ385' which indicates they are calling split by transmitting on 144.370MHz BUT listening on 144.385 MHz for replies, this avoids congestion. When the original station hears your reply on 144.385MHz they then QSY to 144.385 MHz and both stations complete the QSO on .385. They do not work split after the CQ is answered.

    

Shown below is a still image of my FSK441 QSO (using WSJT software) with ES6RQ on 21.12.2003 on 144.360 MHz a distance of 1116 miles and my best DX via Meteor Scatter so far. The burst captured below shows the signal I received from my friend 'Ants' in Estonia. I was only using 50 watts with my FT-847 and a 9 element Tonna Yagi at 150m asl to reply and you can see my MS signal report received in Estonia of 27.

A map of Stations I have worked on 144MHz Meteor Scatter from IO84 is shown below. The maximum practical range for MS QSOs is considered to be around 2200km, with my best distance so far being 1796km. I have managed to work stations via MS in Iceland, France, Germany, Poland, Estonia, Czech Republic, Italy, Switzerland, Croatia, Bosnia, Serbia, Slovenia, Norway, England, Holland, Denmark & Spain.

 WEAK SIGNAL (WSJT SOFTWARE) DATA COMMUNICATIONS MODES BY BAND