Emailing: Meteors detected LRO Perseids 12-160823
My results attached from last 3 days - did other folks get same peak time as me?
Andy
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Re: RAZoom Autumn programme
I'm having to rearrange Sept. 1st and Oct. 6th.? Oct 6th now OK.? A new programme will be published soon. Sept. 1st remains open.? I'm thinking we can put a evening together in-house.? If you have any results/observations, instrument comment, data visualisation techniques that may be interesting for a wider audience let me know and I will put an evening together. Otherwise:
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Fri. Oct. 6th
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19:30 BST
(18:30 UTC)
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Dr. Asayama, Shinichiro
Square Kilometre Array Observatory
at Jodrell Bank
National Astronomical Observatory of Japan
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Square Kilometre Array Observatory at Jodrell Bank - an update and an innovative and a fun solution for hydrogen line reception.
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--
???? Paul Hearn? ???? ? paul@...? ???? ?RA Section Director? ???
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Re: Frequency used to detect Graves
Thanks Neil for this great advice
Sent from
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Glad to hear you were able to detect echoes. How confident are you in
the frequency precision of your 817?? Might be worth checking if you
hear a 1kHz tone in USB mode when you are tuned 1kHz below the beacon
frequency.? GB3SEV on Worcestershire is on 144.462, it sends a pure tone
for part of each minute.? The rest is PI4 mode that you can decode using
PI-RX software.? GB3VHF in Kent is on 144.430 and it sends some pure
tone in a two-minute cycle with (I think) JT65 mode in the other
minute.? Another option is to find someone fairly local who has a
GPS-locked transmitter on 2m and get them to send you a carrier on a
known frequency fo you to calibrate against.? It's like that any offset
in frequency on the test signal will be the same on GRAVES.? However, if
setting a wider offset and IF shift works for you, then that's probably
good enough.? You could also try zeroing the IF offset and tuning down
from .049 in 100Hz steps to see where you start seeing meteor pings
again.? You could also do it in reverse, by increasing the tune
frequency in 100Hz steps from .0475 and reducing the IF shift by 100 Hz
steps.? That way you should continue to see the meteors at the original
frequency on SpecLab.? When the IF offset is zero and you are still
seeing the meteors centered at about 1kHz in SpecLab, then your real
tune frequency will be on .049.? Take a note of what the radio says it
the dial frequency at that point and you can see what the difference is
between the real frequency and what the display says.? Most modern
superhets are pretty accurate after they warm up, but the radio might be
off by a few hundred Hz.? Beacons (and friends with frequency-locked
radios) are a useful resource.
Neil
On 14/08/2023 15:52, Andrew Thornett via groups.io wrote:
> Hi All
> During this meteor shower I have successfully detected meteors on my
> Yaesu FT817.
> What I do not understand is why I could not detect these meteors when
> I tuned to 143.049MHz, but could detect them when I tubed to
> 143.0475MHz and then used the offset function on the radio to bring
> the signal into view (not visible on screen until I twirled the offset
> to the right to raise frequency).
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Re: Frequency used to detect Graves
Glad to hear you were able to detect echoes. How confident are you in the frequency precision of your 817?? Might be worth checking if you hear a 1kHz tone in USB mode when you are tuned 1kHz below the beacon frequency.? GB3SEV on Worcestershire is on 144.462, it sends a pure tone for part of each minute.? The rest is PI4 mode that you can decode using PI-RX software.? GB3VHF in Kent is on 144.430 and it sends some pure tone in a two-minute cycle with (I think) JT65 mode in the other minute.? Another option is to find someone fairly local who has a GPS-locked transmitter on 2m and get them to send you a carrier on a known frequency fo you to calibrate against.? It's like that any offset in frequency on the test signal will be the same on GRAVES.? However, if setting a wider offset and IF shift works for you, then that's probably good enough.? You could also try zeroing the IF offset and tuning down from .049 in 100Hz steps to see where you start seeing meteor pings again.? You could also do it in reverse, by increasing the tune frequency in 100Hz steps from .0475 and reducing the IF shift by 100 Hz steps.? That way you should continue to see the meteors at the original frequency on SpecLab.? When the IF offset is zero and you are still seeing the meteors centered at about 1kHz in SpecLab, then your real tune frequency will be on .049.? Take a note of what the radio says it the dial frequency at that point and you can see what the difference is between the real frequency and what the display says.? Most modern superhets are pretty accurate after they warm up, but the radio might be off by a few hundred Hz.? Beacons (and friends with frequency-locked radios) are a useful resource.
Neil
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On 14/08/2023 15:52, Andrew Thornett via groups.io wrote: Hi All
During this meteor shower I have successfully detected meteors on my Yaesu FT817.
What I do not understand is why I could not detect these meteors when I tuned to 143.049MHz, but could detect them when I tubed to 143.0475MHz and then used the offset function on the radio to bring the signal into view (not visible on screen until I twirled the offset to the right to raise frequency).
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Frequency used to detect Graves
Hi All?
During this meteor shower I have successfully detected meteors on my Yaesu FT817.
What I do not understand is why I could not detect these meteors when I tuned to 143.049MHz, but could detect them when I tubed to 143.0475MHz and then used the offset function on the radio to bring the signal into view (not visible on screen
until I twirled the offset to the right to raise frequency).
Forgive my ignorance- I only have the foundation radio licence, which taught me virtually nothing about the science of radio communication!
On another note, I detected max 26 meteors per hour over the weekend during the Perseods - how does this compare to everyone else's peak rates? Am I about right or lower than average?
Also-some of you are producing real time feed from your PCs online - I would love to do that! How do I do it?
Andy?
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It may be as described in attached paper - it seems to occur particularly during Perseids.? ?
See also the regular BRAMS data.
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Hi,
Perseids 2023 results are attached. Time 0300-0600 BST 13th
August with GB3MBA.
My old slow speed cassette recorder has some wow and flutter. I
was also listening on 87.70 Mhz during the night and I heard a few
low level reflections.
Regards ,
Mike D
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On 14/08/2023 09:25, Brian wrote
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Hello Tony? and Andrew
Yes lots of strange shapes to explain.? An easy one is the
spread on the shot with the time stamp at 00:27:48. At about
00:27:10 the spreading is the Beacon identifying itself in fast
CW.? Some "key clicks" are inevitable at that speed.? We
designed the keyer to identify as infrequently as absolutely
necessary and as fast as reasonably possible as it would be
preferable if the beacon transmitted a continuous carrier with
no modulation. Re all the other strange shapes it would be good
to have a discussion to compare our thoughts. Some could be due
to the Meteoroid breaking up with bits shooting off in different
directions ??? I was expecting that head echoes would be
directional so not everyone will see the same head echo but am
beginning to suspect that some meteors burn up without creating
the characteristic head echo? perhaps due to the material from
which they are composed .?? Perhaps only the more metallic ones
produce the characteristic head echo of short duration with
rapid change in Doppler ???
Brian
On 13/08/2023 20:20, Tony Abbey
wrote:
I've seen that detail regularly in the bright reflections. Also
the almost sinusoidal wiggles. The display is only time,
frequency and intensity, so someone could model what's
happening. Maybe Brian knows what they might be.
Tony
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Hello Tony? and Andrew
Yes lots of strange shapes to explain.? An easy one is the spread
on the shot with the time stamp at 00:27:48. At about 00:27:10 the
spreading is the Beacon identifying itself in fast CW.? Some "key
clicks" are inevitable at that speed.? We designed the keyer to
identify as infrequently as absolutely necessary and as fast as
reasonably possible as it would be preferable if the beacon
transmitted a continuous carrier with no modulation. Re all the
other strange shapes it would be good to have a discussion to
compare our thoughts. Some could be due to the Meteoroid breaking
up with bits shooting off in different directions ??? I was
expecting that head echoes would be directional so not everyone
will see the same head echo but am beginning to suspect that some
meteors burn up without creating the characteristic head echo?
perhaps due to the material from which they are composed .??
Perhaps only the more metallic ones produce the characteristic
head echo of short duration with rapid change in Doppler ???
Brian
On 13/08/2023 20:20, Tony Abbey wrote:
toggle quoted message
Show quoted text
I've seen that detail regularly in the bright reflections. Also
the almost sinusoidal wiggles. The display is only time, frequency
and intensity, so someone could model what's happening. Maybe
Brian knows what they might be.
Tony
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Ghosts in the Air Glow Transmissions
For those interested,?: Composition No.3 (Amanda Dawn Christie) will be transmitted from HAARP on 14 August, 0330-0430 UTC.? Frequencies and modes are listed on the "transmission" page of the website here:
?
For those without shortwave receivers, it will be streamed live on the homepage of the project website: .? IEEE Spectrum Article on Amanda's work is here:
?
Amanda's work is funded by the Canada Council for the Arts.?
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Whit -- Whitham D. Reeve Anchorage, Alaska USA ---
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I've seen that detail regularly in the bright reflections. Also the almost sinusoidal wiggles. The display is only time, frequency and intensity, so someone could model what's happening. Maybe Brian knows what they might be.
Tony
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Some brilliant traces Tony.
The ones at bottom that form arcs - what are you picking up there?
Andy
Sent from
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Here's a link to my Google photos folder. I'll put some more screen grabs in there in a moment:
Tony
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Here's a link to my Google photos folder. I'll put some more screen grabs in there in a moment:
Tony
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Hi Tony, the images are heavily compressed by groups.io, can you
save them to Google Drive or some other repository so we can see
then at full resolution perhaps?
--
Neil
On 13/08/2023 00:15, Tony Abbey wrote:
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A couple of images of my receiver compared with Brian's stream. I
was surprised how much detail I was seeing in the long pings
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A couple of images of my receiver compared with Brian's stream. I was surprised how much detail I was seeing in the long pings.   .
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Can I ask how folks are streaming video via the online TV service so we can see them on their websites? I’d like to set mine up to do that too.
Andy
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From: [email protected] <[email protected]>
On Behalf Of Brian via groups.io
Sent: 12 August 2023 21:50
To: [email protected]
Subject: Re: [baa-rag] Perseids by Radio
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Hello Tony
At this stage, the streaming video via BATC is just an interim measure which we have put in place for the Perseids. Meanwhile the team are working on streaming the I/Q data via the server. The next step will be to get similar displays from multiple receivers
accessible? via the server. Once that is in place you, and anyone else interested in studying Meteors will have access to that data which includes precision timing and has the potential for correlating events viewed from different perspectives and for detailed
analysis. So the serious science opportunities start then.? But in the mean time there are other possibilities using the video streams, I noticed a particularly interesting? echo today but was unable to check how it looked on the Devon receiver because I'm
working on other stuff. It would be helpful to capture screenshots from both receivers for such events.
We know the receivers do not always see the same echoes and that their video latency is different but any screenshots of both streams showing the same echoes would be of interest.
All the best
Brian
On 12/08/2023 17:42, Tony Abbey wrote:
Question to Brian - I could obviously fill up this group with 'interesting' looking images from the two receivers, but that's not very bandwidth efficient. So I wondered what science you are doing on the two receivers, and how we can help
out in the field?
Tony
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Hello Tony
At this stage, the streaming video via BATC is just an interim
measure which we have put in place for the Perseids. Meanwhile the
team are working on streaming the I/Q data via the server. The
next step will be to get similar displays from multiple receivers
accessible? via the server. Once that is in place you, and anyone
else interested in studying Meteors will have access to that data
which includes precision timing and has the potential for
correlating events viewed from different perspectives and for
detailed analysis. So the serious science opportunities start
then.? But in the mean time there are other possibilities using
the video streams, I noticed a particularly interesting? echo
today but was unable to check how it looked on the Devon receiver
because I'm working on other stuff. It would be helpful to capture
screenshots from both receivers for such events.
We know the receivers do not always see the same echoes and that
their video latency is different but any screenshots of both
streams showing the same echoes would be of interest.
All the best
Brian
On 12/08/2023 17:42, Tony Abbey wrote:
toggle quoted message
Show quoted text
Question to Brian - I could obviously fill up this group with
'interesting' looking images from the two receivers, but that's
not very bandwidth efficient. So I wondered what science you are
doing on the two receivers, and how we can help out in the field?
Tony
|
Question to Brian - I could obviously fill up this group with 'interesting' looking images from the two receivers, but that's not very bandwidth efficient. So I wondered what science you are doing on the two receivers, and how we can help out in the field?
Tony
|
Re: Frequency and band for Graves for meteor detection for Perseids
Another screenshot
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Thanks VERY?much for taking the time to give me all this advice.
See screenshot - I think I've got it working now! Although the peaks on my Spectrum Lab in Lichfield Staffordshire do not seem to match those from Devon - is that normal?
Andy
Sent from
If you have a traditional analogue superhet radio, you may not have the option to run a wider bandwidth unless it has FM or AM filters that can be switched in while using SSB mode.? In that case, set the tune freq to .049 and
you should get the tropo signal as a 1 kHz tone and any meteor reflections will be audible as pings and will show on the waterfall. It's a very long time since I used a non-SDR radio so I tend to forget about how analogue radios work!
GRAVES will be illuminating whatever it's looking at and that might not be in a great direction for the meteors, so if your antenna is a beam, try aiming off the direct path by up to 20 degrees either way.
With the current tropo conditions, it's quite possible you are hearing the transmission, but it is usually heard the form of an on/off signal as the array switches direction.
From here in Yorkshire, it usually looks like this:
I stood outside for 15 minutes staring up at the sky and saw nothing other than a lot of stars and a couple of satellites.
That central line is the troposcatter signal.
In this plot of an elevated 9-ele yagi following the international space station, there aren't many meteors, you you can see the characteristic periodicity of the transmission
Neil
On 11/08/2023 23:54, Andrew Thornett via groups.io wrote:
Hi Neil,
This is embarrassing.....but try as I might I csnt work out how to set the settings you mention - not sure I understand them all.
Actually my radio is Yaesu FT817 - I got model number wrong previously.
I have set it to USB on 143.049MHz and then turned off AGC. I then used IF shift (see attached page from manual) and rotated knob until carrier wave appeared and moved to central 2500Hz on Spectrum Lab - was that the right thing to do?
I cannot work out how to set bandwidth at 5KHz in manual anywhere.......
Help! I'm not seeing any meteor pings.
Andy
Sent from
Thanks Neil
Sent from
Hi Andrew, I usually set my IF bandwidth to 5 kHz in USB mode and set the local osc 2.5 kHz low so the carrier appears at 2.5 kHz in the baseband output into SpecLab. When I'm using GRAVES to monitor LEO satellites or the ISS, the
doppler can be over 10 kHz to get the full S curve so I use the IF data stream from my Elad FDM-DUO SDR to give me at least 24 kHz bandwidth for the waterfall. Moon doppler from Graves changes fairly slowly so I update the radio tune frequency once a second
from the WSJT-X tracker so the moon echo can be received in a narrow bandwidth to look at artefacts in the received signal.
If your radio has a fixed filter bandwidth, try offsetting the tune frequency 1 kHz low in USB or 1 kHz high in LSB so you can get a reasonable range of doppler shifts within the radio bandwidth to analyse in SpecLab
Neil
> On 11 Aug 2023, at 11:34, Andrew Thornett via groups.io
<andrew@...> wrote:
>
> ?
> Dear All,
> After several years hiatus and watching this group from afar, I am now restarting radio astronomy. I have set up my aerial to detect radio scatter from Graves.
> Please could someone confirm for me that best frequency is 143.050MHz using upper or lower side band? I think I am picking up the carrier but over last 24 hours so obvious meteor pings.
> If I can get this sorted today then I can monitor through the Persoed shower tomorrow and hopefully detect the peak.
> Using Yaesu FT891 radio, the aerial is off the shelf 144MHz and currently at 2.5m above ground on Clansman poles. Using Spectrum Lab.
> I attach a current screenshot.
> Andy
>
>
>
Attachments:
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Re: Frequency and band for Graves for meteor detection for Perseids
Thanks VERY?much for taking the time to give me all this advice.
See screenshot - I think I've got it working now! Although the peaks on my Spectrum Lab in Lichfield Staffordshire do not seem to match those from Devon - is that normal?
Andy
Sent from
toggle quoted message
Show quoted text
If you have a traditional analogue superhet radio, you may not have the option to run a wider bandwidth unless it has FM or AM filters that can be switched in while using SSB mode.? In that case, set the tune freq to .049 and
you should get the tropo signal as a 1 kHz tone and any meteor reflections will be audible as pings and will show on the waterfall. It's a very long time since I used a non-SDR radio so I tend to forget about how analogue radios work!
GRAVES will be illuminating whatever it's looking at and that might not be in a great direction for the meteors, so if your antenna is a beam, try aiming off the direct path by up to 20 degrees either way.
With the current tropo conditions, it's quite possible you are hearing the transmission, but it is usually heard the form of an on/off signal as the array switches direction.
From here in Yorkshire, it usually looks like this:
I stood outside for 15 minutes staring up at the sky and saw nothing other than a lot of stars and a couple of satellites.
That central line is the troposcatter signal.
In this plot of an elevated 9-ele yagi following the international space station, there aren't many meteors, you you can see the characteristic periodicity of the transmission
Neil
On 11/08/2023 23:54, Andrew Thornett via groups.io wrote:
Hi Neil,
This is embarrassing.....but try as I might I csnt work out how to set the settings you mention - not sure I understand them all.
Actually my radio is Yaesu FT817 - I got model number wrong previously.
I have set it to USB on 143.049MHz and then turned off AGC. I then used IF shift (see attached page from manual) and rotated knob until carrier wave appeared and moved to central 2500Hz on Spectrum Lab - was that the right thing to do?
I cannot work out how to set bandwidth at 5KHz in manual anywhere.......
Help! I'm not seeing any meteor pings.
Andy
Sent from
Thanks Neil
Sent from
Hi Andrew, I usually set my IF bandwidth to 5 kHz in USB mode and set the local osc 2.5 kHz low so the carrier appears at 2.5 kHz in the baseband output into SpecLab. When I'm using GRAVES to monitor LEO satellites or the ISS, the
doppler can be over 10 kHz to get the full S curve so I use the IF data stream from my Elad FDM-DUO SDR to give me at least 24 kHz bandwidth for the waterfall. Moon doppler from Graves changes fairly slowly so I update the radio tune frequency once a second
from the WSJT-X tracker so the moon echo can be received in a narrow bandwidth to look at artefacts in the received signal.
If your radio has a fixed filter bandwidth, try offsetting the tune frequency 1 kHz low in USB or 1 kHz high in LSB so you can get a reasonable range of doppler shifts within the radio bandwidth to analyse in SpecLab
Neil
> On 11 Aug 2023, at 11:34, Andrew Thornett via groups.io
<andrew@...> wrote:
>
> ?
> Dear All,
> After several years hiatus and watching this group from afar, I am now restarting radio astronomy. I have set up my aerial to detect radio scatter from Graves.
> Please could someone confirm for me that best frequency is 143.050MHz using upper or lower side band? I think I am picking up the carrier but over last 24 hours so obvious meteor pings.
> If I can get this sorted today then I can monitor through the Persoed shower tomorrow and hopefully detect the peak.
> Using Yaesu FT891 radio, the aerial is off the shelf 144MHz and currently at 2.5m above ground on Clansman poles. Using Spectrum Lab.
> I attach a current screenshot.
> Andy
>
>
>
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Last night, I took some screendumps of interesting reflections that could be seen in both receivers. Image 2 shows the morse ident on Brian's rx but not on the Norman Lockyer one. Tony   
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Paul Hearn
WReeve
