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SteveNickolls

New to Meteor Detecting

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Hi,

I have been wanting to branch out into meteor work for some time so I was really pleased when the June & July 2014 issues of the Sky at Night magazine ran articles on how to build a system capable of receiving signals from reflected meteor ion trails. The project fortunately wasn't too technical and my aerial was constructed from materials available from a local large DIY store. I decided to install the aerial mounted horizontally to lessen the visual effect on neighbours and it is around 4 meters off the ground with the supporting post being securely bolted to a shed. I used Google Earth to help align the aerial with the radar site in Dijon using local landmarks. I finished installing the aerial on Wednesday together with the FUNcube Dongle Pro+ and software and it has already detected lots of sporadic meteors. I have run the coaxial cable from the aerial in plastic conduit and into the house allowing me to operate everything in the comfort of the living room. I still have the large user manual to read through to get the most out of the set up and I was wondering if other forum members have been similarly inspired to make their own systems? I can certainly see its uses when visible observing is prohibited by cloud and add to the overall experience of astronomy. I am looking forward to using the set up when a predicted meteor shower is due.

Cheers,

Steve

post-23098-0-70504500-1404463343_thumb.j

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and I was wondering if other forum members have been similarly inspired to make their own systems?

Yes, I have been similarly inspired but am currently weighing this up against a totally different Solar System project - namely the Daystate Quark ! As a licensed radio ham, I should have most of what I need already BUT I sold all my radio gear to get started in astronomy ...... I still have a 5/8 wave vertical on my roof tuned for both 2 metres and 7cm so I *may* be able to press this into service and just add the FUNcube Dongle Pro+.

Decisions, decisions ..... so much to have a go at, so little time :grin:

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Hi,

Thanks very much Jeremy for the link to the thesis, I have just finished page 12 and it is all so fascinating. I knew there was a lot to learn and this just proves it! Still it will stimulate the grey matter marvellously. Good luck Steve whichever route you take-meteors or the solar system project. Do post on SGL whichever way you do decide to go. I was very much into learning amateur radio in my 20's but my other studies and life in general meant my interest went onto the back burner. Now retired I have time to devote to things of interest and while programming and maths will both always remain weak points to me I will enjoy learning and doing what I can.

Thanks again.

Cheers,

Steve

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Yes, I have been similarly inspired but am currently weighing this up against a totally different Solar System project - namely the Daystate Quark ! As a licensed radio ham, I should have most of what I need already BUT I sold all my radio gear to get started in astronomy ...... I still have a 5/8 wave vertical on my roof tuned for both 2 metres and 7cm so I *may* be able to press this into service and just add the FUNcube Dongle Pro+.

Decisions, decisions ..... so much to have a go at, so little time :grin:

Greetings Steve. I was a radio amateur many years ago (ex. VK8WJ ) but got sick of electronics so I let my licence lapse. We used to have a string of Ionosonde stations near the equator to predict/ study trans- equitorial propagation. But sundry hurricanes and a couple of tsunamis wiped the whole lot out!

If you set up a chirpped sounder in your yard You might get a few complaints. Yes?

Jeremy.

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Thanks for the suggestion Jeremy but I will have to pass on that one. :evil:  I have finished reading the thesis btw, a very interesting and informative read. When I read of the very high temperatures in the atmosphere I was startled having always thought the atmosphere got colder the higher up it went. It also prompted me to see, using Google Earth what the view would be looking down on the earth from 80-120km where most meteors are detected. Thanks again for a thought provoking and enlightening read.

Cheers,

Steve

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My perspective, from a chap who has never addressed this particular problem:

I never thought of the problem of detecting meteors nor why I would want to detect them but this problem is a very interesting one and I find it intriguing, worth researching and thinking about. I usually ask myself questions and try to find the answers. Meteor detection presents a problem of sizable proportions. And, initially, a few questions arise:

Where do I find these Meteor events? Are the events evenly distributed over the sky? Is there available a time/ frequency distribution of meteor events available or do I have to find out for myself? .... This answer to the last question is quite a difficult problem to model mathematically and test ... But , with apologies to Stephen Fry, Quite Interesting.

Going hand in hand with the problem as to where these events occur is the question of detectability.

How do we detect a meteor event? Perhaps we use the the powerful broadcast transmitters ( FM, TV etc.) as a "sought of " bi-static radar (?) OK so we use a "radar" then what will the reflected signal look like? How do I model this situation? Is there a characteristic or signature that distinguishes this particular signal from all others? Of course there will be given the high speed nature of the event ... The doppler shift in frequency of the reflected signal. The doppler frequency will be quite complex in itself as it comes from a rapidly de-accelerating body. The meteor itself, because of its small size, is not being tracked but the plasma in its wake so the "doppler spectrum"

will be an important part of the signature. The timing associated with this event will have its own particular signature as the body is being entering the atmosphere. So as we can see the signature of a signal from a meteor event will have a complex and varying time/frequency/amplitude nature. I imagine that the radar signature of the meteor is "huge" given that it causes this ionised "vapour trail".

The issue of using these broadcast transmitters as radar transmitters presents even more intriguing problems as the broadcast signal is very strong compared to the reflection how do we see only the reflection? Or remove the broadcast signal and see only the reflections? May be easier to develop ones own CW radar ... At least one has more control over it!!

As you can see Steve for someone , like me, who has never addressed the problem before I would have to do a lot more research. I will start this research by doing some reading to enlighten my self. Perhaps if the scope of the work could be, initially, reduced one will have a much greater chance of success. By reducing the scope I mean look for known events as we know about their times and region of the sky. This should produce a most interesting result when one compares the events of simple visual observation and electronic observation.

What an interesting problem. Many thanks for raising it.

Jeremy

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I was lucky enough to attend a talk by Paul Hyde, who wrote the article in S@N magazine, a couple of months ago at my local astronomy club and that really inspired a few people to give it a go. I personally thought the FUNCube Dongle is quite expensive, but fortunately another member of our group, a little more technically minded than me, came up with a much cheaper alternative using a KEEDOX DVB-T USB TV RTL-SDR FM+DAB Radio Tuner Receiver Stick (£10 from Amazon) and some additional software: HDSR (High Definition Software Defined Radio) downloaded for free from http://www.hdsdr.de/. Including the cost of building the aerial, the whole system costs less than £50 to build and the results are just as good. As a result, I will be giving this a go myself - more as a mini science project with my son than anything, but it'll make a nice change from staring at cloudy skies every evening.

I

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Hi,

I have been wanting to branch out into meteor work for some time so I was really pleased when the June & July 2014 issues of the Sky at Night magazine ran articles on how to build a system capable of receiving signals from reflected meteor ion trails. The project fortunately wasn't too technical and my aerial was constructed from materials available from a local large DIY store. I decided to install the aerial mounted horizontally to lessen the visual effect on neighbours and it is around 4 meters off the ground with the supporting post being securely bolted to a shed. I used Google Earth to help align the aerial with the radar site in Dijon using local landmarks. I finished installing the aerial on Wednesday together with the FUNcube Dongle Pro+ and software and it has already detected lots of sporadic meteors. I have run the coaxial cable from the aerial in plastic conduit and into the house allowing me to operate everything in the comfort of the living room. I still have the large user manual to read through to get the most out of the set up and I was wondering if other forum members have been similarly inspired to make their own systems? I can certainly see its uses when visible observing is prohibited by cloud and add to the overall experience of astronomy. I am looking forward to using the set up when a predicted meteor shower is due.

Cheers,

Steve

attachicon.gifIMG_2259 - Copy.JPG

I would like to try but I misted how to make the dipole can you post how you made it

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Steve et all,

Greetings...

I too will be giving this project a go plus try to complete my SDR Telescope once winter weather chases me inside

You may want to google SDR# pronounced SDR SHARP an outstanding and free SDR (IQ) software

Another free and outstanding down load is SpectrumLab with IQ and LO conversion, wonderful filters and many options plus BITE (built in test equipment) it will also port to EXCEL and IRFANVIEW another free and outstandind image handler

ham since 1957

retired 1997

73 John

N3AAZ

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I was lucky enough to attend a talk by Paul Hyde, who wrote the article in S@N magazine, a couple of months ago at my local astronomy club and that really inspired a few people to give it a go. I personally thought the FUNCube Dongle is quite expensive, but fortunately another member of our group, a little more technically minded than me, came up with a much cheaper alternative using a KEEDOX DVB-T USB TV RTL-SDR FM+DAB Radio Tuner Receiver Stick (£10 from Amazon) and some additional software: HDSR (High Definition Software Defined Radio) downloaded for free from http://www.hdsdr.de/. Including the cost of building the aerial, the whole system costs less than £50 to build and the results are just as good. As a result, I will be giving this a go myself - more as a mini science project with my son than anything, but it'll make a nice change from staring at cloudy skies every evening.

I

Hi Dave

Just got one of those cheapo Keedox sticks you mentioned and seems to work fine under the Windows software that it comes with (BlazeHD tv)  but I seem to be struggling with getting HDSR to see it, don`t suppose you could remember how Paul did it in his talk and maybe give a quick `how to`? no probs if not I`ll just keep trying different settings :smiley:

cheers

Steve

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Hi Dave

Just got one of those cheapo Keedox sticks you mentioned and seems to work fine under the Windows software that it comes with (BlazeHD tv) but I seem to be struggling with getting HDSR to see it, don`t suppose you could remember how Paul did it in his talk and maybe give a quick `how to`? no probs if not I`ll just keep trying different settings :smiley:

cheers

Steve

Hi Steve,

It wasn't Paul Hyde that used HDSDR - it was one of our club members - Paul uses the software that comes with the FUNCube dongle. However, what you need to do is:

1. Do not install the software that came with the tuner dongle - if you have already done this then uninstall it.

2. Download ExtIO_RTL2832.dll (device specific .dll) from https://github.com/josemariaaraujo/ExtIO_RTL/raw/master/Release/ExtIO_RTL.dll and place it in the HDSDR folder in your program directory.

3. Download and install ZADIG (Device driver installer) from http://zadig.akeo.ie/

4. Insert dongle, then start ZADIG and press 'install driver', click options, list all devices, choose 'RTL2832' or if not showing then 'Bulk In, Interface (Interface O)' , click 'install driver.

5. Connect ariel and turn on signal booster.

6. Start HDSDR and do the following:

a. Click on ExtIO and select source (RTL2832)

b. Set Tuner AGC off (unticked)

c. Set RTL AGC off

d. Set Offset Tuning on

e. Set sample ratio 1.02 Msps

f. Set buffer size 64kb

7. Select FM and select a known radio frequency in both LOA and Tune (i.e. 95.5 MHz would be 095,500,000).

8. Set bandwidth (F6) to 19200

9. Press Start (F2). You should now hear the audio and see this displayed in the waterfall

10. Return bandwidth to 12000, select USB (upper sideband) and tune Graves Radar Beacon (143.049 MHz). You need to offset slightly, so the tuner should look like this:

LOA 0143.073.384

Tune 0143.048.800

11. Adjust the bandwidth zoom in the lower spectrum to 0-800 Hz and if all is well you should see and hear meteors.

I hope this helps.

Regards,

David

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Excellent reply Dave many thanks for that, yes I did install the stuff that came with the dongle so will uninstall it and try your method. No doubt a few of us will benefit from your instructions :smiley:

cheers

Steve

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Yes I can confirm those instructions are spot on Dave thanks again. Managed to get HDSDR to see the dongle and I`m getting audio from it. I just need to knock up the proper aerial for it now!.

I have an old FM stereo aerial with long elements which can be cut and made to Paul`s dimensions in the mag!.

best

Steve

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I would like to try but I misted how to make the dipole can you post how you made it

Hi mbhyde, have sent you a personal message with details that I hope you can follow :-) Good luck with your build.

Cheers,

Steve

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Hi folks, me again! I have made up my mind and for now, wonderful though the Quark is, I am just not sufficiently interested in imaging the Sun and am quite content to admire the works of others - when it comes to imaging, I am a deep sky kinda guy and will concentrate on that. However, combining my earlier passion for amateur radio with astronomy has much appeal at far less cost.

Tempting though the Funcube is, I've gone for a Newsky TV28T RTL2832U/R820T RTL-SDR USB Stick which I *think* will do what I want, if not, then as a minimum, I will have FM radio in my observatory! Frequency coverage is not as wide as the Funcube but it covers the region that I am mostly interested in for this project. Projected delivery is Wednesday of this week so I have already downloaded SDR # and and Spectrum Lab. The latter seems a little unpredictable as although it displays 'noise' from my soundcard it doesn't always output it through the sound system whereas SDR# seems consistent.

I am rather excited about the dongle's imminent arrival and will keep you posted on my progress or lack of it!

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Hi guys

Happy to report the aerial/dongle and Hdsdr seem to be talking to each other and first light last night gave me a few radio stations but sadly no meteors yet! I had to play about with the various settings in HDSDR to get any sound but once found was as clear as a bell. Like Steppenwolf if it doesn't work I'll at least have a radio in the obs ;-)

Thanks again for the info Dave!

Sterve

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To try and pre-empt any problems, are there any other transmitters to consider using if there is an issue with Graves? My take-off to the South East (and South generally) is not great. Maybe a delivery today? :grin:

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Yippee, the SDR dongle has arrived and I have it singing all over the music FM bands. I can get both SDR# and HDSDR to work but have to have the RF gain turned up pretty high - is this normal?

Pleased so far BUT (there's always a but!!) I cannot get Spectrum Lab to work as I expected. Feedback through from the laptop's built in microphone I can get in spades! I have loaded the FM Receiver configuration file from the S @ N magazine article (but this was designed specifically for the FunCube dongle so may not be relevant) and this stops the feedback but I just get a continuous colour trace down the centre of the monitor.

Any pointers on what should be running (concurrently ?) and what settings I should be looking at adjusting in Spectrum Lab would be much appreciated!

A new journey begins ................

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steppenwolf, et all

Greetings,

SpectrumLab is one of the most complex (for me, a very steep learning curve) yet flexable, TNX!!! DL4YHF, radio/soundcard analyzers out there. It comes with love and easy to modify labor of those before us. Outstanding applacation specific files can be loaded, run, modified and saved.

Click >File, then >LoadSettingsFrom, then >configurations, then your choice of two dozen or so to include one RTLspecific and several IQ SDR, there is a help file (maybe on the web) that discusses function and personality of most.

One reason to detect meteors, because there out there,

another, from ham radio standpoint, their ionized tails make outstaning radio frequency reflectors that rebroadcast our signals to other parts of the hemisphere.

72, 73

John

N3AAZ

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Wow it's great that so many of us are 'having a go' with meteor detecting. It's been a good learning curve for sure and I'm very grateful to Jeremy (JRWASTRO) for his link to information on meteors which is a really fascinating read. My aerial has been operating for almost 4 weeks now and has withstood fairly strong winds and several intense downpours that we seem to get nowadays so I'm keeping my fingers crossed for when the winter weather comes-at least if the weather is bad at any time I can be snug and warm indoors watching and listening to the detected trails. The FUNcube Dongle Pro+ has worked flawlessly and is both recording numerical data and screen shots for me to pour through. I wish I was in any way proficient at writing instructions for the Spectrum Lab software but the 'out of the box' settings seem to be enough for me right now. I'm looking forward to reviewing the screen shots and trying to figure out explanations for the different shapes of the ionised trails (and the occasional satellite). I have had the system running during the Delta Aquarids shower and will repeat for the Perseids. Best wishes to everyone 'having a go'.

Cheers,

Steve

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John, (N3AAZ)

Thank you for your reply. I have tried the rtl_sdr_test.usr configuration file and generally it seems to be working and recognising the memory stick but I cannot hear any audio output. Any suggestions for why this might be as I can hear the audio well on both SDR# and HDSR.

73 G4OAK

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Steve

I get exactly the same as you apart from no visible waterfall in Speclab, how did you get that please?.

Sdr# and Hdsdr works fine with good sound but no meteors seen yet, not sure how often they should be seen or if I have the settings right yet but getting something via Speclab would be good!

Cheers

Steve

Edited by Gasman

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steppenwolf, et all

Greetings,

I've not run rtl_sdr_test, but have run and modified several SDR_IQ 'configurations'.

Check to see if SL knows your I/O device, click Options, then Audio settings, then Audio IQ, then Input Device/Pipe and then Output/Pipe. I strongly suggest not to change any sampling rates at this time, but

trouble shoot using SL's built in test equipment (BITE).

Click Components, then click Show Components (circuit window), then click Components again then click Time domain scope.

Check out BITE'S Signal Generator and notice level setting options both on the sig gen and the amplisiers, click specific amp to make its slider active.

John

N3AAZ

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Hi John,

Still getting nowhere with Spectrum Lab and I have concluded that I am not after all getting a proper waterfall trace. Below is what I am getting. I have checked the Pipe/driver and my device is not present and I cannot find a way of locating it.....

post-1029-0-61259500-1406813568_thumb.pn

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