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Meteor Echoes - Perseids 2019

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#1 WernerRoland

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Posted 11 August 2019 - 09:30 AM

To any anyone interested, I have a live stream off my SDR meteor detection on YouTube. Some fantastic echoes coming through, especially early mornings. Try HD view for some good resolution. https://www.youtube....I0nm4ygt4w/live


Edited by WernerRoland, 11 August 2019 - 09:32 AM.

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#2 Jim in Sweden

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Posted 11 August 2019 - 09:35 AM

Ha! I was the first to hit the thumbs up there. Can you share any information about your rig? I am interested in starting up here in Sweden, but am concerned about the distance to the GRAVES radar in France, the common signal source here in Europe. We are 2000km away. I have been told it will work, but I am a beginner at meteor scatter. What's your opinion? Cool live feed, I will follow the next few days. We have a meteor camera online for our astronomy club, you can see it here: http://www.astro.uu.se/~meteor/VARF/

click around on the links, some take you to latest events, video, and other data about the Swedish network.

Thanks!

Jim 


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#3 WernerRoland

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Posted 11 August 2019 - 09:41 AM

Thanks Jim. I will definitely share my setup details with you, later today. Currently still in recovery mode. Had a waterlogged tree branch take down the power line a few houses down from me. Created a major EMI transient in all my gear. Fortunately only took out a couple of USB audio dongles, but my precious RSPs are ok.  



#4 WernerRoland

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Posted 11 August 2019 - 09:49 AM

BTW Jim, for starters you can check my blog (see profile.) I started it specifically to document some of my setups. And other stuff I'm interested in.



#5 Aquarellia

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Posted 11 August 2019 - 11:49 AM

Super idea to post this here!  I ear a nice one @16h22 UTC

This very morning in 30 minutes we saw 15 perseids and 2 sporadics

Good job. Bravo !

Michel


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#6 WernerRoland

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Posted 11 August 2019 - 01:00 PM

Super idea to post this here!  I ear a nice one @16h22 UTC

This very morning in 30 minutes we saw 15 perseids and 2 sporadics

Good job. Bravo !

Michel

Thanks Michel ! I'm glad to hear somebody gets to see this besides me and friends. I primarily set this up as a side line to my meteor echo recording (i.e. image captures of echoes) reliability test. Thought if I have this continuous stream into my computers why not also stream to YouTube. I just commissioned a homebuild yagi specifically designed for the frequency I'm monitoring (55.24 Mhz), and also switched to an RSP1A (from RTL dongle.) This has greatly improved the quality of the echoes I'm getting. I'll post a few later.

 

Werner



#7 Jim in Sweden

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Posted 11 August 2019 - 03:00 PM

Fantastic information on your blog. And I have seen some great ringing echoes on the feed! On your blog your screenshots have some data on the right side of the screen. Is that not in the live feed?



#8 S.Boerner

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Posted 11 August 2019 - 08:18 PM

Id be interested in hearing about your homebuild yagi.  I didn't see anything about it in your blog. 

 

Tks


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#9 WernerRoland

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Posted 12 August 2019 - 05:54 AM

Fantastic information on your blog. And I have seen some great ringing echoes on the feed! On your blog your screenshots have some data on the right side of the screen. Is that not in the live feed?

The streaming SW (OBS Studio) allows you to select a portion of the app's window you're streaming. I've trimmed out the app (Spectrum Labs) menu and side bars, including the audio frequency scale and spectrum on the right.

 

Werner



#10 WernerRoland

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Posted 12 August 2019 - 05:56 AM

Id be interested in hearing about your homebuild yagi.  I didn't see anything about it in your blog. 

 

Tks

 

Will post something on that this upcoming weekend. It was a lot more work than I expected. But the results justify the work.

 

Werner



#11 happylimpet

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Posted 12 August 2019 - 06:03 AM

To any anyone interested, I have a live stream off my SDR meteor detection on YouTube. Some fantastic echoes coming through, especially early mornings. Try HD view for some good resolution. https://www.youtube....I0nm4ygt4w/live

I dont suppose someone could explain what we're seeing? I assume an echo will show as a bright feature at the emitted frequency, or do we see doppler shifts? Is the 908/901 the emitted frequency?


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#12 WernerRoland

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Posted 12 August 2019 - 08:06 AM

Correct, these are the Doppler shifts, centered on 900 Hz with a display band of 100 Hz. The 908/901 is where I had my cursor resting, which I’ve moved off screen now.



#13 Jim in Sweden

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Posted 12 August 2019 - 01:19 PM

How would an earth grazer leave a trail in the ionosphere strong enough to reflect a signal? The studies I have read show the meteor passing tangent to an arc centered between receiver and transmitter. Have I misunderstood? Any guides where I can learn how to interpret the signals present in your waterfall stream? I have seen some real bombs! Some ring for well over a minute.



#14 WernerRoland

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Posted 12 August 2019 - 05:05 PM

Jim, I assume that was you earlier on YouTube? Let me start by saying I'm a mechanical engineer with good knowledge of computers, signal conditioners, and software. When it comes to meteor echoes though I consider myself a novice. That being said, I'm assuming an earth-grazer is not much different from other meteors other than it comes in tangent to earth instead of at a downward angle (duh.) So as long as it's big enough to not vaporize while it passes through the upper atmosphere I would think it shows up like any other meteor, maybe with an echo that starts lightly, grows in strength, and then fades away. One factor that affects the trails is vertical wind shear in the upper atmosphere. I'm just starting to read up on that. I'm posting a couple of snapshots which IMO depict meteors essentially exploding into multiple pieces with each piece then leaving it's own trail. BTW just scrolling through what I've captured in the last couple days … wow. I'll have to post some later.

 

Perseids-capt34596
Perseids-capt34576
Perseids-capt34530

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#15 happylimpet

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Posted 13 August 2019 - 01:39 AM

Very cool, well done for getting all this! 

 

If the reflections come off the plasma rather than the debris itself, I dont get why there's a doppler shift  - surely the plasma stops moving quite quickly?


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#16 Jim in Sweden

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Posted 13 August 2019 - 01:52 PM

Interesting comments here! Yes, I was responding to another comment on the youtube chat. That said, I have been watching all day now for two days at work, and have seen some totally amazing signals. Now we just have to figure out what they mean! I'm new at this, as well, so together we go into the void. I am going to attend the International Meteor Conference in Germany in October, so I have some questions for those guys! Your signals look different from other similar sites, they seem to contain much more details. As for the Doppler shifting, this is frequency shift, so the signals below the transmitters freq are lower in the visual image, right? The comments above about the plasma/debris influencing the doppler signal is a good question. As far as the tangential reflection about which I asked, that may be true for shortwave communications using meteor scatter, and something quite different for signal visualization. I am not certain.

 

I saw one trail that left a perfectly symmetrical tapering tail, ringing like crazy for at least a minute or two. This one is similar but not quite as perfect.

 

Here is a visual image corresponding to all this radar stuff :p You see much more than we do!

meteor shower composite Med size

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#17 EricTheCat

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Posted 13 August 2019 - 06:22 PM

To any anyone interested, I have a live stream off my SDR meteor detection on YouTube. Some fantastic echoes coming through, especially early mornings. Try HD view for some good resolution. https://www.youtube....I0nm4ygt4w/live

Very nice setup.  I've been running a meteor detection system on and off since around 2007.  I believe using the same station as yours (I currently monitor 53.30967 Mhz CW).  What direction is your Yagi is pointed?  I don't have a yagi that works well for that band and so never was able to decisively say which direction I pick up the echos from.  I have been using a quadrifilar helix antenna but also get good results using a dipole.

 

Thanks for sharing!

Eric


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#18 WernerRoland

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Posted 13 August 2019 - 06:51 PM

Jim and HappyLimpet, here's a couple of articles on some of your questions. First one has some good info about meteor echo interpretation. Second one is a bit more science orientated, and interesting reading.

 

https://www.britastr...rs_by_RADAR.pdf

https://arxiv.org/ft.../1502.03307.pdf


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#19 WernerRoland

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Posted 13 August 2019 - 07:39 PM

Very nice setup.  I've been running a meteor detection system on and off since around 2007.  I believe using the same station as yours (I currently monitor 53.30967 Mhz CW).  What direction is your Yagi is pointed?  I don't have a yagi that works well for that band and so never was able to decisively say which direction I pick up the echos from.  I have been using a quadrifilar helix antenna but also get good results using a dipole.

 

Thanks for sharing!

Eric

 

Thanks Eric. And Hello! I know of your work, have read several posts on your blog. You're in southern Minnesota I believe. I'm in Northeast MPLS, surrounded by big trees, with a hill that I need to aim my antenna over. I built the Yagi last week, with parts from Menards and ACE hardware. I'll post something on that this weekend, S. Boener was interested. It's aimed up around 40 degrees, pointing East-Northeast. Frequency I'm tuned to is 55.240100 Mhz. I also see lots of activity at 55.26 Mhz, and I don't know where that's coming from. The meteor traces there don't seem to be the same as seen at 55.24 Mhz.  However if there's a big one it will show on both. It's possible they are detecting the same meteor but reflecting differently. I don't know much about the nature of analog TV signals, but know they span 6 Mhz with info (audio FM, sync pulses, etc) spread throughout. I'm reading up on that. I also happen to have an old NTSC pattern generator, and oscilloscope. Might end up frying a dongle experimenting. smirk.gif I'll add some snapshots of the dual meteor echoes in a bit. Haven't quite figured out how to add images to gallery without leaving the forum.

 

Capture7
Capture2
Capture4

Edited by WernerRoland, 13 August 2019 - 07:44 PM.

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#20 WernerRoland

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Posted 13 August 2019 - 09:05 PM

Jim, super that you're going to a Meteor Conference in Deutschland! I'm just starting to study up on how Doppler shifts as applied to meteor echoes works. I'm starting with hand calculations of classic (acoustic) Doppler physics which of course equally works for RF frequencies, and then will work trigonometry into it. Best way to learn and understand IMO. I'll be adding captures to my albums and you are welcome to use them for technical discussions. I've got 2 computers running, capturing at different speeds and resolutions. The one I'm streaming is sort of pretty, but that setup totally saturates with big ones. I just ordered a new (refurbished) computer, a HP Z440 workstation 6 core 3.5 GHz CPU, to crank up the resolution on the meteor echoes FFTs. Sorta excited about that. grin.gif 

 

I'm glad you're getting use out of the stream. The live chat thing can get strange. Many trolls.

 

Werner



#21 t_image

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Posted 13 August 2019 - 11:19 PM

Thanks for sharing!waytogo.gif

I like seeing people doing this (thought it was getting more difficult due to shutdown/conversion of most analog TV transmitters....

 

One factor that affects the trails is vertical wind shear in the upper atmosphere.

Yes, so I'm doing a rare thing of capturing bright meteors in high res video,

and sometimes I'm able to see the winds do fun things to the trails while they are still glowing...

 

There are also a few still images that are recently revealing particular meteors may be spiraling (rotationally) as they pass through/by....

I definitely don't have the smarts to consider that factor and it's radio reflective signal. Just thought I'd share.....

 

Here's two high res animated GIF's I posted on another site illustrating video of rapid drift of lit trails:

 

wavvy.png

^quick image stack composite to tease watching the animated links:

 

https://4.img-dprevi...ed3328c1a3dcbc1

https://4.img-dprevi...b6541e076d0e975

 

Both were shot at 30frames per second realtime original 4K video, so the white-hot meteor head is extended due to motion blur.

 

 I'm constantly finding the video gives lots more information on quick meteors compared with the oft image of a meteor resolved in a long exposure image....

 

I suspect the audio reflection science you all are doing here is analogous...

 

 


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#22 happylimpet

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Posted 14 August 2019 - 05:10 AM

Thanks for sharing!waytogo.gif

I like seeing people doing this (thought it was getting more difficult due to shutdown/conversion of most analog TV transmitters....

 

Yes, so I'm doing a rare thing of capturing bright meteors in high res video,

and sometimes I'm able to see the winds do fun things to the trails while they are still glowing...

 

There are also a few still images that are recently revealing particular meteors may be spiraling (rotationally) as they pass through/by....

I definitely don't have the smarts to consider that factor and it's radio reflective signal. Just thought I'd share.....

 

Here's two high res animated GIF's I posted on another site illustrating video of rapid drift of lit trails:

 

attachicon.gif wavvy.png

^quick image stack composite to tease watching the animated links:

 

https://4.img-dprevi...ed3328c1a3dcbc1

https://4.img-dprevi...b6541e076d0e975

 

Both were shot at 30frames per second realtime original 4K video, so the white-hot meteor head is extended due to motion blur.

 

 I'm constantly finding the video gives lots more information on quick meteors compared with the oft image of a meteor resolved in a long exposure image....

 

I suspect the audio reflection science you all are doing here is analogous...

Holy crap those gifs are the best and coolest things Ive seen in a long time! Well done!!



#23 WernerRoland

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Posted 14 August 2019 - 06:36 AM

Very nice Timage! The duration of the meteor captures are close to the sharp pings I hear, maybe around 200 msec. A while back I actually recorded the audio stream coming off my setup, and the played back various pings and longer duration events, and did spectral analysis on them. A lot of work to sift through all that. Once I get my new computer up and running I'm going to have another go at it. It would be interesting to extract frequencies and amplitudes from stills of the "smoke" trails of your captures.


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#24 EricTheCat

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Posted 14 August 2019 - 04:51 PM

Thanks Eric. And Hello! I know of your work, have read several posts on your blog. You're in southern Minnesota I believe. I'm in Northeast MPLS, surrounded by big trees, with a hill that I need to aim my antenna over. I built the Yagi last week, with parts from Menards and ACE hardware. I'll post something on that this weekend, S. Boener was interested. It's aimed up around 40 degrees, pointing East-Northeast. Frequency I'm tuned to is 55.240100 Mhz. I also see lots of activity at 55.26 Mhz, and I don't know where that's coming from. The meteor traces there don't seem to be the same as seen at 55.24 Mhz.  However if there's a big one it will show on both. It's possible they are detecting the same meteor but reflecting differently. I don't know much about the nature of analog TV signals, but know they span 6 Mhz with info (audio FM, sync pulses, etc) spread throughout. I'm reading up on that. I also happen to have an old NTSC pattern generator, and oscilloscope. Might end up frying a dongle experimenting. smirk.gif I'll add some snapshots of the dual meteor echoes in a bit. Haven't quite figured out how to add images to gallery without leaving the forum.

 

Thank you for the information.  I really appreciate it.   I had a typo, I'm really monitoring 54.30967 Mhz.  This is close to 54.31 Mhz which is the ATSC pilot frequency.  From what I'm reading, 55.25 is the video carrier of the same channel but I'm not sure if that reference refers to pre-digital TV transition.

 

Some stations remained on VHF and just switched to the digital protocol after the digital TV transition.

 

Did you point ENE to point toward a particular station, or just where the signals came in the best?  I ask because my friend and I were initially suspecting that my echos are coming off of a station in South Dakota but we were never 100% confident on that.  

 

I just tried a quick test and sure enough 55.240 works well from here so far.  I will have to do some testing to see if it does any better.  Once I got detection on the ATSC pilot I didn't think to try for other pilots in the channel range.

 

Fun stuff. :)



#25 EricTheCat

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Posted 14 August 2019 - 04:52 PM

t_image, I just want to say I have always enjoyed your meteor animations.  Truly an inspiration. :)


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