EXCITEMENT IS IN THE AIR!

 
Meteor Shower, Aurora Sporadic-E and Solar Flares detected using Radio Signal Reflection
(aka The G7IZU Radio Reflection Detection Page) by Andy Smith G7IZU.


May 2012: My meteor activity alert system is currently inactive due to the closure of
the majority of VHF analogue TV transmitters in Europe.
Testing is currently underway to find a new signal to power this website.

Scroll down for more information, or click go directly to the LIVE FFT page.

Get live data and alerts via web pages, blog, email, and now Twitter!

Also a VLF solar flare detector!

What is "G-7-I-Z-U"? It's my amateur radio callsign...

Please do not abuse these pages by embedding images on websites without permission!

My copyright notice can be read here.
 

Geminds 2010

Some graphs of my observations of the Geminids can be seen here.

Stargazing Live



The 2012 BBC Stargazing Live event took place between Jan 16th and 18th.

This year I'm very proud to say that I was a part of the show.
I was the BBC Engineering Manager at the Dulverton Outside Broadcast.

The Jodrell Bank meteor-detection system was inspired by this website,
and put into action by Megan Argo.



Daily meteor activity received by G7IZU

The Radio Meteor Detection Hobby - The Imminent Threat!

The casual hobby of radio meteor detection using the powerful signal source of analogue TV transmitters is now at  an end. Under European directives, most analogue TV transmitters will have now shut down.

The hunt is now on to find alternative signal sources before doom and despondency descends heavily upon the hobby. In western Europe there are a couple of alternatives, but they are not the whole solution. ONERA in France has helpfully provided an extremely powerful carrier wave satellite radar in the VHF band. As well as spotting satellites, it's also very good at spotting meteor trails. This radar is useful to observers in Western Europe as far north as the southern UK. Another alternative is a pair of 50W meteor transmitters set up by a Belgian group on frequencies close to 50 MHz. The useful range of these is only a couple of hundred kilometres.

There are now also other proposals coming forward, involving a possible UK network of linked meteor "radar" transmitters and observers, run in conjunction with various astronomical facilities. Amateur radio beacons
may also useful, although their low power will be limiting.

These is early days in these ideas, but the future is looking more promising for this hobby.

Andy, 01.05.2012 
 

PAST ENDEAVOURS

The Sky at Night

Andy Smith and David Entwistle appeared on the BBC's "The Sky at Night" meteor special "Meteor Mania" on BBC 4 TV on November 25th, 2007. If you missed it, it can be downloaded in Windows Media format from here:

meteormania.wmv (Dur 29m29s, 192MB).

It may also be viewed in Real Player format at the BBC's "The Sky at Night" homepage. The regular monthly editions of the programme may be viewed in Real Player format on the site.

"The Sky at Night" co-presenter and co-author of "Bang! The Complete History of the Universe",
Chris Lintott, FRAS, held a live radio-meteor/astronomy demonstration on the fourth plinth in
Trafalgar Square for one hour, as part of artist Antony Gormley's "One & Other" project
on August 14th 2009.
 

The full local RRD site index can be found here.

PARTIAL G7IZU RRD SYSTEM DIAGRAM (UNTIL MAY 2012)

 
FIREBALL AND EVENT ARCHIVE
   
I'm uploading radio fireball and other "events" to a third party photo hosting site. 
 

The latest five events - click on them to view. More Radio Fireball Events from G7IZU

 

LIVE FFT Spectrum analysis
The main page updates every minute. I also have an archive page showing hourly captures from the past 24 hours. 

The main live page consists of an FFT screen, showing the audio pass bands from two ssb radio receivers, which are tuned to two European VHF TV channels. To the top left is a meteor activity indicator. Below the FFT is a panel showing various solar, auroral and ionospheric warning indicators. Below that is a graph which shows a four-day history of the meteor activity rate, along with a record of echo durations. If echo durations are high, this indicates that constant carriers may be present in the form of sporadic E or aurora. Meteors entering the atmosphere within the reflection range of distant transmitters cause signal reflections to show on the FFT display in various ways, dependant on their size, direction of travel, and the ability of the ionized trail left by the meteor to reflect the signal. More information about this can be found further down the page. The Spectrum Lab program, which creates the FFT and graph charts, counts the meteor "pings" and generates the information required for the activity indicators and alert email system.

 
Read on to find out more about what this stuff is all about, but beware that some pages are quite graphics-heavy. 
A broadband connection is recommended, along with a screen size of 1024x768.

Please consider making a donation towards the running of this website. 
Considerable time, effort and investment has gone into creating it.
 
It's quite expensive in electricity running the equipment, and 
I've also just had to invest in commercial webspace.
 
If the site is to continue and expand, it needs money. Please donate, however little.
Donations are made instantly through Paypals' secure server using the button above.
 
Thankyou! Andy.
 

 
  
The latest FFT plot. Click here to open the live FFT page.

Please note that the system is now in a "test" mode and data displayed will appear fairly random. 

Overview of the system

LIVE SPORADIC-E maps are available

This is a LIVE map of sporadic E clouds over Europe. If they are around, they're marked as yellow dots, which are the mid-points of amateur radio contacts on 50 or 144 MHz via Es mode, during the last 30 minutes. These are sourced from an application called "LiveMUF" which monitors the amateur DX Cluster network for Es contacts, then plots them on maps of Europe and the world. The Es map page is here.
 
Further details about my radio observation station can be found here: [How-to setup a Radio Meteor Obs. Station]. Please note that some of the information there is now very out of date, so do not expect things to work first time if you're trying it yourself!

European TV stations present on these frequencies cannot be received via direct ground wave propagation. Any other mode of propagation that bounces the signal in my direction is detectable, such as sporadic E, meteor reflection, auroral reflection, reflections from high-flying aircraft or even re-entering spacecraft and debris. Coronal Mass Ejections from the sun become visible as the ionosphere is bombarded by protons from the sun. Doppler shifts of a few tens of hertz can be observed, caused by the ionized trails of meteors or debris drifting in the winds of the upper atmosphere, sometimes for several minutes on end. Sometimes the head of the meteor itself is large enough to register a swift Doppler shift of a few kHz over fractions of a second. A meteor shower, such as the Quadrantids (above) can keep the FFT display constantly active. In contrast, sporadic E events, during late spring to early autumn, can wipe out the display with strong carriers for hours and days at a time. Radio auroras can appear almost as wonderful as their visual counterparts, which, of course, would be visible outside if it wasn't cloudy/daytime/you live in a city etc. etc.

The image above is a very good example of an auroral signal. It was recorded on 31st Oct 2003 between 0010 and 0110 GMT, during the second night of big auroras over the UK. Visible in the sky over Plymouth were various red glows and an arc of white stretching overhead. The signal is spread out due to the rapid Doppler shift caused by the charged particles in the auroral curtain rapidly moving. Several TV carriers, which are a few hundred hertz apart, are being reflected simultaneously, making the Doppler effect appear bigger than it really is. 
 

Above is shown a typical busy meteor period. The upper part of the trace is monitoring the Eastern European channel R2, on 59.258 MHz. The spots are caused by "underdense" meteors. The lower part of the trace has a few "underdense" meteors, but also one quite heafty "overdense" trail lasting a few minutes. This might have been classed as a "fireball" had it been visually sighted.
 

This is an example of how a Sporadic E (Es) opening looks. Signal levels can be extremely high, and the receivers' AGC levels are often compressed. Here, two carriers only 6 Hz apart are visible on Channel R2. Also visible in the lower trace are the typical 50Hz harmonic lines from the analogue TV transmitter in Sweden. 

Another Sporadic E opening, showing how the signals can stop coming from one direction or location, and turn to another. Here TVE Spain gives way to RTP Portugal. The wobbling Portugese signal is caused by the transmitter frequency drifting in a 10 minute cycle, due to poor TX frequency control or local mains frequency instabilities at the TX site.

Above: Strong meteor echoes.

Above is what I believe to be a sign of a coronal mass ejection from the sun causing the ionosphere to become charged. The effect is similar to an aurora, with noise-like Doppler. See the Doppler shift in the lower trace go from negative to positive? I'm looking for an explanation of this. (See also the CME page)

For daily update announcements about this site, click the blog link at the top of every page.

Browser issues
This site is written using MS FrontPage 2002. Therefore, it's best viewed using  IE6 or later. Netscape 7.2 appears to give good results, as does Opera 7.5. Google Chrome woks well. There may be a slight problem with Mozilla Firefox and some other browsers. Some table cells are incorrectly sized and take their measurements from the background image within, rather than from the specified cell sizes, and make some pages look messy. If you spot any other problems please let me know. I will always attempt to resolve problems.

Andy.

About this site and the author, a reviewer said recently (copied here as published):

G7i7u Radio Reflection Detection Site

This guy if i understand correctly is an extroardinary amatuer, and judging by the amount of info on this page,probably has a brain the size of sweden, but its worth a visit every now and then if your bored or planning something
 
Dont worry i haven't got one giant eye like galileo, or sir patrick moore, i dont understand harf of it myself but its interesting all the same, i find inhaling sharply on a blend of your choice, then exhailing slowly through the nose usually does the page no harm at all.  [As posted by "Gotdelot "to www.ukcultivator.org. Gee, thanks! Why stop at Sweden?]
 

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