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Re: Meteor echo of the day

 

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Hello Brian

There is good evidence that receivers of Graves meteor scatter in central southern England can detect scatter from meteors over NE France and the English Channel (e.g. Fleet, R., “Correlating video meteors with GRAVES radio detections from the UK”, in International Meteor Conference Mistelbach, Austria, 2015, p. 30). A meteor detected travelling across the GB3MBA region in a south easterly direction could pass over NE France soon thereafter and could account for my detection of it a few seconds later.

Chris

On 30/12/2024 15:36, Brian wrote:

Hello Chris

Yes could be the same one. It's rather uncertain as to how Graves can illuminate an event that occurs in the region covered by? GB3MBA. Graves runs very high power and I see a strong direct signal here virtually all the time. It could be backscatter from the troposphere ??

Brian

On 30/12/2024 11:54, Chris Holt wrote:

I'm just catching up on emails. The time stamps below look to be 11:07:45 on 28/12/2024. If so, I have captured Graves NEO radar reflections from the same meteor at 11:07:48 via my horizontally polarised Yagi in West Oxfordshire - see attached Spectrum Lab screenshot.

Regards

Chris


On 28/12/2024 11:13, Brian wrote:

Seasons greetings.?

There's still plenty going on ! Do feel free to make your own live observations at:- . Here is a screenshot captured just now.

Note the same echo observed from different directions one of which uses Horizontal and Vertical polarisation.

All the best

Brian
Re: Meteor echo of the day

 

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Hello Chris

Yes could be the same one. It's rather uncertain as to how Graves can illuminate an event that occurs in the region covered by? GB3MBA. Graves runs very high power and I see a strong direct signal here virtually all the time. It could be backscatter from the troposphere ??

Brian

On 30/12/2024 11:54, Chris Holt wrote:

I'm just catching up on emails. The time stamps below look to be 11:07:45 on 28/12/2024. If so, I have captured Graves NEO radar reflections from the same meteor at 11:07:48 via my horizontally polarised Yagi in West Oxfordshire - see attached Spectrum Lab screenshot.

Regards

Chris


On 28/12/2024 11:13, Brian wrote:

Seasons greetings.?

There's still plenty going on ! Do feel free to make your own live observations at:- . Here is a screenshot captured just now.

Note the same echo observed from different directions one of which uses Horizontal and Vertical polarisation.

All the best

Brian
Re: Meteor echo of the day

 

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I'm just catching up on emails. The time stamps below look to be 11:07:45 on 28/12/2024. If so, I have captured Graves NEO radar reflections from the same meteor at 11:07:48 via my horizontally polarised Yagi in West Oxfordshire - see attached Spectrum Lab screenshot.

Regards

Chris


On 28/12/2024 11:13, Brian wrote:

Seasons greetings.?

There's still plenty going on ! Do feel free to make your own live observations at:- . Here is a screenshot captured just now.

Note the same echo observed from different directions one of which uses Horizontal and Vertical polarisation.

All the best

Brian

event20241228_110815_4.jpg

Voyager 1

 

Quite a challenge!
Re: Meteor echo of the day

 

Thanks for sharing.? What do you make of it???
BTW it is not possible for me to read data and time from screen image ... and it would be useful for comparisons.?
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Mike
Meteor echo of the day

 

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Seasons greetings.?

There's still plenty going on ! Do feel free to make your own live observations at:- . Here is a screenshot captured just now.

Note the same echo observed from different directions one of which uses Horizontal and Vertical polarisation.

All the best

Brian
UKRAA help required

 

A bit off topic, but UKRAA are looking for someone who has DXF creating and editing experience for some assistance - only a small question - !? If you can help, please contact Paul Hearn.? Apologies for this but cries for help in the past have on this channel have yielded some great expertise.
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???? Paul Hearn? ???? ?paul@...? ???? ?RA Section Director? ???
Re: Magnetometer problems

 

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Thanks David

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From: [email protected] <[email protected]> On Behalf Of David Farn via groups.io
Sent: 22 December 2024 17:06
To: [email protected]
Subject: Re: [baa-rag] Magnetometer problems

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Andy,

Can you get the magnetometer board on the bench with a DVM ?

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Does the analogue output change as you move the board. There are many reasons why the outputs could be up jammed up high or low, but the obvious thing to check out are the supply voltages, maybe you have lost the negative rail.

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If the analogue output of the board is normal and does alter, it probably is a problem with you Labjack connection.

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David

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From: [email protected] On Behalf Of Andrew Thornett via groups.io
Sent: 22 December 2024 09:59
To: '[email protected]' <[email protected]>
Subject: [baa-rag] Magnetometer problems

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Can I ask for some help with my UKRAA magnetometer – the trace is appearing as below – I am using an older UKRAA magnetometer with parallel port – so data collected using the analogue outputs and Labjack U3.

Andy

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Virus-free.

Re: Magnetometer problems

 

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Andy,

Can you get the magnetometer board on the bench with a DVM ?

?

Does the analogue output change as you move the board. There are many reasons why the outputs could be up jammed up high or low, but the obvious thing to check out are the supply voltages, maybe you have lost the negative rail.

?

If the analogue output of the board is normal and does alter, it probably is a problem with you Labjack connection.

?

David

?

?

From: [email protected] On Behalf Of Andrew Thornett via groups.io
Sent: 22 December 2024 09:59
To: '[email protected]' <[email protected]>
Subject: [baa-rag] Magnetometer problems

?

Can I ask for some help with my UKRAA magnetometer – the trace is appearing as below – I am using an older UKRAA magnetometer with parallel port – so data collected using the analogue outputs and Labjack U3.

Andy

?

?

?

?

?

Virus-free.
Magnetometer problems

 

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Can I ask for some help with my UKRAA magnetometer – the trace is appearing as below – I am using an older UKRAA magnetometer with parallel port – so data collected using the analogue outputs and Labjack U3.

Andy

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?

?

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Live feed Geminid meteor shower from Lichfield Radio Observatory

 

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Watch live feed of meteors in the Geminid Meteor Shower being detected from Lichfield, UK, by radio meteor scatter on 143.049MHz by clicking on the link below:

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Geminids

 

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Do enjoy the Geminids at:-

Brian
Anyone in the UK doing VLBI? (or FLBI perhaps...)

 

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Is anyone doing amateur long-baseline interferometry in the UK? I'd characterise it as "fairly-long baseline", say up to 200km, so timing constraints are not in the "H-maser in the basement" class. Maybe using DiFX?

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Neil
Re: “the effects of satellite megaconstellations on radio astronomy”.

 

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I think the existing protections for the 4.8 GHz and 14.5 GHz H2CO maser lines should prevent problems for my future plans, as I'm in the protection zones for both Jodrell and Cambridge. Whether there are sufficient interesting bright sources with emission or absorption lines for my little 3m solid dish to detect remains to be seen. Main issue is going to be when a satellite starts spraying spurs when it goes faulty - after all they are designed to use cheap parts and be disposable. If they have a viable deorbit or shutdown system, that sort of problem would only be temporary. Same applies to the 22GHz rotational water line and 23.87GHz ammonia inversion line

Overload of receive mixers and LNAs by the satellite signals, causing reciprocal mixing or intermodulation is a potential problem where they transmit a strong signal in the 30 GHz region that will be received efficiently by a high-gain dish with a waveguide horn and feed on lower frequencies.? That will be slightly worse than the light reflection lines in light astronomy as it will cause problems even when they are not reflecting sunlight. You could argue that the problem is in the receive kit though, so we could protect ourselves somewhat by using better receiver/antenna designs.

I haven't done the calculations, but is there any risk from specular reflections (like Iridium flares) causing spurious continuum or solar thermal lines to appear in cold sky with high gain antennas? I guess no amateurs have a sharp enough 1.4 GHz system for it to be a problem, and at higher frequencies, the albedo of the reflective bits of the sats and their tiny areas, plus the small beam size will mean they are dim and very rare.

What about the thermal emissions from waste heat and solar thermal absorption? As the sats are low powered and fairly isotropic, and with the proportion emitted in the micrpowave/mmWave frequency bands being a tiny proportion of the total thermal radiation, the issue is like trying to detect a hot-water bottle full of cold water in low earth orbit from its microwave thermal emissions.

Not for publication in the consultation, but I'm trying to work out ways to use those beastly lumps of metal as passive reflectors for long range communications at frequencies they are not using. I suspect Physics is not on my side with the transmit power I'm allowed to use though.? Might as well make use of them for something. I also look forward to finding if we can use their eventual de-orbit re-entry burnups as meteor-style reflectors. Something positive to look forward to!
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Neil
Re: "the effects of satellite megaconstellations on radio astronomy".

 

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I study forward scatter meteors using the GRAVES transmitter in FRANCE on 143.050 MHz. Satellites also scatter and considerable QRM is detected. At the moment I can disentangle the satellite’s scattered signal from my data with post processing but some meteor data is caught up in this.? I can send more info if needed.

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Regards

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Mike

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Mike German

Hayfield in High Peak

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Re: “the effects of satellite megaconstellations on radio astronomy”.

 

first thought is it will depend very much on the frequencies that are use by the satellites but also how much radio noise they emit that will make it much harder to discern actual signals. First article I cam across, no idea on its accuracy
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Re: “the effects of satellite megaconstellations on radio astronomy”.

 

Hi Brian?
I've noticed a few news articles on the BBC news site mentioning this over the last couple of years.
Here is a link to one article
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There were a few more, but this maybe a good starting point.
Regards
Stephen
G4VBD
“the effects of satellite megaconstellations on radio astronomy”.

 

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I have been asked to comment on “the effects of satellite megaconstellations on radio astronomy”. Has anyone any thoughts they could share?

Brian
Cosmic ray muon measurement at a global scale and the associated applications - Now Online Professor Xiaochun He

 

Hi
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Radio Astronomy Section Zoom Friday the 6th Dec 2024
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Cosmic ray muon measurement at a global scale and the associated applications. By Professor ?Xiaochun He

Video is now on YouTube?
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You can find links to previous meeting videos and associated materials?
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Kind Regards
John B
Re: EUCARA25 Save the date.....

 

I'll be there! Fantastic coup for guest speaker

Mike German
High Peak
Hayfield
201 - 220 of 1993