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Hallo J-L, ? I have looked at your link to the FRIPON data base and it is a most useful resource; thanks FRIPON for sharing! The echo validation showing GRAVES data overlaid on video data is something we are striving for in the UK and Ireland. ??For a “manual validation” it must have used a small army of analysts J? I think you have mentioned in the past that the link between Radio and video is subjective based on times being roughly aligned – can you say more?? Also you classify head echo, trail echo and both; are you able to identify underdense and overdense ionisation? Do you class the “head echo” as the Doppler shifted frequency part that end near zero?? I have seen the backscatter plots showing separation between head and trail and I am not convinced that he entire downward shift is true head echo.? We could discuss this off forum? ? ? ? ? Regards ? Mike --- ? ???? ?/\ ??_/\/? \ ?/??????? \/\ ? Mike German Hayfield in High Peak ?
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From: [email protected] [mailto:[email protected]] On Behalf Of Rault Jean-L.
Sent: 18 March 2021 13:39
To: [email protected]
Subject: Re: [baa-rag] MSID (Meteor SID)? Hi Mike Nice to meet you on this list ! As you can read in the papers you are refering to, I was using at that time a simple VHF receiver to detect meteors, thanks to their GRAVES pings. But now that our FRIPON programme with its 100 video cameras is delivering accurare meteor trajectories data, I just started to cross correlate the VLF MSID I recorded with the meteor trajectory(ies) computed by FRIPON. Because of my current poor health, (thank you for your last gift of a grape), this work is progressing very slowly at the moment, but I'll keep you informed of any success (or failure) in identifying the metor trajectories responsibles for MSIDs. Jean-Louis P.S.: Please remember that we offer free access to our FRIPON data base (). So you can search yourself for any correlations between the meteor pings or VLF phenomenons you observed and the corresponding meteor trajectories we computed Below is a map showing the trajectories of the meteors we observed theses last few months on VHF and on video (blue: tail echoes, red: head echoes, violet: both) Le 18/03/2021 à 11:37, Mike German via groups.io a écrit?: Yes, a challenging subject Paul. ?Thanks Jean-Louis and Paul, for making me aware of the papers which I have read with much interest. ?I was aware of the detailed work of David Morgan on VLF emissions from meteor plasma (BAA RAG website) but not the perturbation of VLF propagation?by ionisation trails. ? ? In the earlier paper that you referenced J-L you mentioned that video was also included in the measurement approach. Did they capture any of the events and provide meteor trajectory details and how was the (very reasonable) ?that the meteor appeared to have passed through a general line between TX and RX.? It appears that not only does one need the meteor to be tangential to an ellipsoid with foci at receiver and GRAVES ( the condition for for the VHF specular trail of forward scatter) but also it is bounded by the ellipsoids centred on receiver and VLF transmitter. ?As with all meteor observations it depends primarily on geometry. It would seem that the observation site would not only need to be in an optimal location from the point-of-view of geometry but also in be "quiet" electromagnetically. It would also, in my mind, be the task for a dedicated station. (BAA funding??) Finally J-L, did you have any particular aspect of the phenomenon in mind with your suggestion? ?
On 16 Mar 2021, at 10:54, Paul Hyde via groups.io <g4csd@...> wrote: ? As Jean-Louis surmises, the SID VLF data would not be suitable for investigating VLF emissions from instabilities in meteor plasma trails.? SIDs are of the order of tens of minutes to hours and the timings collected in observations reflect this.? If meteor-produced VLF pings exist (being provocative here!) they are more likely to be of the order of a fraction of a second. As I understand it, there is statistical evidence that the number of short duration VLF events increases dramatically during meteor showers, but it has been very difficult to distinguish between a meteor-produced VLF spike and the huge number created by other mechanisms, lightning in particular.? Lightning storms in Brazil (for example) generate VLF/ULF pulses that travel around the world. It's a fascinating subject and I know that Jean-Louis has done a lot of work here, see A challenging investigative exercise! On Tuesday, 16 March 2021, 09:02:19 GMT, Rault Jean-L. <f6agr@...> wrote: Hi John B. Yes, there is a SID data base available as explained by John Cook. However, I wonder if it could be used to search for meteor SID. The solar SID are "long duration" events (10 seconds or more) and the meteor SID are "short duration" events (a few seconds or less). So I wonder if the parameters of the existing solar SIDS softwawares (integration parameter) are well adapted for detecting the metor SIDS Jean-Louis ? Le 15/03/2021 à 22:21, John Berman via groups.io a écrit?: Jean-Louis?
this sounds interesting, do we have a SID database,
if not and we think there maybe some mileage perhaps start a new topic and let’s discuss
john B
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A problem with GRAVES is that the illuminating beams step across the sky in a 4.8 second cycle.? So you can't use timestamps to correlate video and radio events with certainty.? The plasma trail coud have formed a couple of seconds before it's illuminated by a radar beam.
Paul Hyde
On Thursday, 18 March 2021, 17:01:26 GMT, Mike German via groups.io <mike.german@...> wrote:
Hallo J-L, ? I have looked at your link to the FRIPON data base and it is a most useful resource; thanks FRIPON for sharing! The echo validation showing GRAVES data overlaid on video data is something we are striving for in the UK and Ireland. ??For a “manual validation” it must have used a small army of analysts J? I think you have mentioned in the past that the link between Radio and video is subjective based on times being roughly aligned – can you say more?? Also you classify head echo, trail echo and both; are you able to identify underdense and overdense ionisation? Do you class the “head echo” as the Doppler shifted frequency part that end near zero?? I have seen the backscatter plots showing separation between head and trail and I am not convinced that he entire downward shift is true head echo.? We could discuss this off forum? ? ? ? ? Regards ? Mike --- ? ???? ?/\ ??_/\/? \ ?/??????? \/\ ? Mike German Hayfield in High Peak ?
From: [email protected] [mailto:[email protected]] On Behalf Of Rault Jean-L.
Sent: 18 March 2021 13:39
To: [email protected]
Subject: Re: [baa-rag] MSID (Meteor SID) ? Hi Mike Nice to meet you on this list ! As you can read in the papers you are refering to, I was using at that time a simple VHF receiver to detect meteors, thanks to their GRAVES pings. But now that our FRIPON programme with its 100 video cameras is delivering accurare meteor trajectories data, I just started to cross correlate the VLF MSID I recorded with the meteor trajectory(ies) computed by FRIPON. Because of my current poor health, (thank you for your last gift of a grape), this work is progressing very slowly at the moment, but I'll keep you informed of any success (or failure) in identifying the metor trajectories responsibles for MSIDs. Jean-Louis P.S.: Please remember that we offer free access to our FRIPON data base (). So you can search yourself for any correlations between the meteor pings or VLF phenomenons you observed and the corresponding meteor trajectories we computed Below is a map showing the trajectories of the meteors we observed theses last few months on VHF and on video (blue: tail echoes, red: head echoes, violet: both) ![]()
Le 18/03/2021 à 11:37, Mike German via groups.io a écrit?: Yes, a challenging subject Paul. ?Thanks Jean-Louis and Paul, for making me aware of the papers which I have read with much interest. ?I was aware of the detailed work of David Morgan on VLF emissions from meteor plasma (BAA RAG website) but not the perturbation of VLF propagation?by ionisation trails. ? ? In the earlier paper that you referenced J-L you mentioned that video was also included in the measurement approach. Did they capture any of the events and provide meteor trajectory details and how was the (very reasonable) ?that the meteor appeared to have passed through a general line between TX and RX.? It appears that not only does one need the meteor to be tangential to an ellipsoid with foci at receiver and GRAVES ( the condition for for the VHF specular trail of forward scatter) but also it is bounded by the ellipsoids centred on receiver and VLF transmitter. ?As with all meteor observations it depends primarily on geometry. It would seem that the observation site would not only need to be in an optimal location from the point-of-view of geometry but also in be "quiet" electromagnetically. It would also, in my mind, be the task for a dedicated station. (BAA funding??) Finally J-L, did you have any particular aspect of the phenomenon in mind with your suggestion? ?
On 16 Mar 2021, at 10:54, Paul Hyde via groups.io <g4csd@...> wrote: ? As Jean-Louis surmises, the SID VLF data would not be suitable for investigating VLF emissions from instabilities in meteor plasma trails.? SIDs are of the order of tens of minutes to hours and the timings collected in observations reflect this.? If meteor-produced VLF pings exist (being provocative here!) they are more likely to be of the order of a fraction of a second. As I understand it, there is statistical evidence that the number of short duration VLF events increases dramatically during meteor showers, but it has been very difficult to distinguish between a meteor-produced VLF spike and the huge number created by other mechanisms, lightning in particular.? Lightning storms in Brazil (for example) generate VLF/ULF pulses that travel around the world. It's a fascinating subject and I know that Jean-Louis has done a lot of work here, see A challenging investigative exercise! On Tuesday, 16 March 2021, 09:02:19 GMT, Rault Jean-L. <f6agr@...> wrote: Hi John B. Yes, there is a SID data base available as explained by John Cook. However, I wonder if it could be used to search for meteor SID. The solar SID are "long duration" events (10 seconds or more) and the meteor SID are "short duration" events (a few seconds or less). So I wonder if the parameters of the existing solar SIDS softwawares (integration parameter) are well adapted for detecting the metor SIDS Jean-Louis ? Le 15/03/2021 à 22:21, John Berman via groups.io a écrit?: Jean-Louis?
this sounds interesting, do we have a SID database,
if not and we think there maybe some mileage perhaps start a new topic and let’s discuss
john B
Attachments:
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Paul, ? I believe there is something worthwhile that can be seen from GRAVES timing – I may have something for a Poster next zoom ! ? ? ? ? Regards ? Mike --- ? ???? ?/\ ??_/\/? \ ?/??????? \/\ ? Mike German Hayfield in High Peak ?
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Show quoted text
From: [email protected] [mailto:[email protected]] On Behalf Of Paul Hyde via groups.io
Sent: 18 March 2021 17:29
To: [email protected]
Subject: Re: [baa-rag] MSID (Meteor SID) ... but straying into Radio Video comparisons? A problem with GRAVES is that the illuminating beams step across the sky in a 4.8 second cycle.? So you can't use timestamps to correlate video and radio events with certainty.? The plasma trail coud have formed a couple of seconds before it's illuminated by a radar beam. On Thursday, 18 March 2021, 17:01:26 GMT, Mike German via groups.io <mike.german@...> wrote: Hallo J-L, ? I have looked at your link to the FRIPON data base and it is a most useful resource; thanks FRIPON for sharing! The echo validation showing GRAVES data overlaid on video data is something we are striving for in the UK and Ireland. ??For a “manual validation” it must have used a small army of analysts J? I think you have mentioned in the past that the link between Radio and video is subjective based on times being roughly aligned – can you say more?? Also you classify head echo, trail echo and both; are you able to identify underdense and overdense ionisation? Do you class the “head echo” as the Doppler shifted frequency part that end near zero?? I have seen the backscatter plots showing separation between head and trail and I am not convinced that he entire downward shift is true head echo.? We could discuss this off forum? ? ? ? ? Regards ? Mike --- ? ???? ?/\ ??_/\/? \ ?/??????? \/\ ? Mike German Hayfield in High Peak ? ? Hi Mike Nice to meet you on this list ! As you can read in the papers you are refering to, I was using at that time a simple VHF receiver to detect meteors, thanks to their GRAVES pings. But now that our FRIPON programme with its 100 video cameras is delivering accurare meteor trajectories data, I just started to cross correlate the VLF MSID I recorded with the meteor trajectory(ies) computed by FRIPON. Because of my current poor health, (thank you for your last gift of a grape), this work is progressing very slowly at the moment, but I'll keep you informed of any success (or failure) in identifying the metor trajectories responsibles for MSIDs. Jean-Louis P.S.: Please remember that we offer free access to our FRIPON data base (). So you can search yourself for any correlations between the meteor pings or VLF phenomenons you observed and the corresponding meteor trajectories we computed Below is a map showing the trajectories of the meteors we observed theses last few months on VHF and on video (blue: tail echoes, red: head echoes, violet: both) Error! Filename not specified. Le 18/03/2021 à 11:37, Mike German via groups.io a écrit?: Yes, a challenging subject Paul. ?Thanks Jean-Louis and Paul, for making me aware of the papers which I have read with much interest. ?I was aware of the detailed work of David Morgan on VLF emissions from meteor plasma (BAA RAG website) but not the perturbation of VLF propagation?by ionisation trails. ? ? In the earlier paper that you referenced J-L you mentioned that video was also included in the measurement approach. Did they capture any of the events and provide meteor trajectory details and how was the (very reasonable) ?that the meteor appeared to have passed through a general line between TX and RX.? It appears that not only does one need the meteor to be tangential to an ellipsoid with foci at receiver and GRAVES ( the condition for for the VHF specular trail of forward scatter) but also it is bounded by the ellipsoids centred on receiver and VLF transmitter. ?As with all meteor observations it depends primarily on geometry. It would seem that the observation site would not only need to be in an optimal location from the point-of-view of geometry but also in be "quiet" electromagnetically. It would also, in my mind, be the task for a dedicated station. (BAA funding??) Finally J-L, did you have any particular aspect of the phenomenon in mind with your suggestion? ? ? On 16 Mar 2021, at 10:54, Paul Hyde via groups.io <g4csd@...> wrote: ? As Jean-Louis surmises, the SID VLF data would not be suitable for investigating VLF emissions from instabilities in meteor plasma trails.? SIDs are of the order of tens of minutes to hours and the timings collected in observations reflect this.? If meteor-produced VLF pings exist (being provocative here!) they are more likely to be of the order of a fraction of a second. As I understand it, there is statistical evidence that the number of short duration VLF events increases dramatically during meteor showers, but it has been very difficult to distinguish between a meteor-produced VLF spike and the huge number created by other mechanisms, lightning in particular.? Lightning storms in Brazil (for example) generate VLF/ULF pulses that travel around the world. It's a fascinating subject and I know that Jean-Louis has done a lot of work here, see A challenging investigative exercise! On Tuesday, 16 March 2021, 09:02:19 GMT, Rault Jean-L. <f6agr@...> wrote: Hi John B. Yes, there is a SID data base available as explained by John Cook. However, I wonder if it could be used to search for meteor SID. The solar SID are "long duration" events (10 seconds or more) and the meteor SID are "short duration" events (a few seconds or less). So I wonder if the parameters of the existing solar SIDS softwawares (integration parameter) are well adapted for detecting the metor SIDS Jean-Louis ? Le 15/03/2021 à 22:21, John Berman via groups.io a écrit?: Jean-Louis?
this sounds interesting, do we have a SID database,
if not and we think there maybe some mileage perhaps start a new topic and let’s discuss
john B
Attachments:
|
Dear Mike
I don't want to clutter up this baa-rag list with too many
technichal? details, so I'm going to discusse with you off forum
Cheers
Jean-Louis
Le 18/03/2021 à 18:01, Mike German via
groups.io a écrit?:
toggle quoted message
Show quoted text
Hallo
J-L,
?
I
have looked at your link to the FRIPON data base and it is a
most useful resource; thanks FRIPON for sharing!
The
echo validation
showing GRAVES data overlaid on video data is something we
are striving for in the UK and Ireland. ??For a “manual
validation” it must have used a small army of analysts J?
I think you have mentioned in the past that the link between
Radio and video is subjective based on times being roughly
aligned – can you say more?? Also you classify head echo,
trail echo and both; are you able to identify underdense and
overdense ionisation? Do you class the “head echo” as the
Doppler shifted frequency part that end near zero?? I have
seen the backscatter plots showing separation between head
and trail and I am not convinced that he entire downward
shift is true head echo.? We could discuss this off forum?
?
?
?
?
Regards
?
Mike
---
?
????
?/\
??_/\/?
\
?/???????
\/\
?
Mike
German
Hayfield
in High Peak
?
?
Hi Mike
Nice to meet you on this list !
As you can read in the papers you are refering to, I was
using at that time a simple VHF receiver to detect meteors,
thanks to their GRAVES pings.
But now that our FRIPON programme with its 100 video cameras
is delivering accurare meteor trajectories data, I just
started to cross correlate the VLF MSID I recorded with the
meteor trajectory(ies) computed by FRIPON.
Because of my current poor health, (thank you for your last
gift of a grape), this work is progressing very slowly at the
moment, but I'll keep you informed of any success (or failure)
in identifying the metor trajectories responsibles for MSIDs.
Jean-Louis
P.S.: Please remember that we offer free access to our FRIPON
data base (). So
you can search yourself for any correlations between the
meteor pings or VLF phenomenons you observed and the
corresponding meteor trajectories we computed
Below is a map showing the trajectories of the meteors we
observed theses last few months on VHF and on video
(blue: tail echoes, red: head echoes, violet: both)
Le 18/03/2021 à 11:37, Mike German via
groups.io a écrit?:
Yes, a challenging subject Paul. ?Thanks
Jean-Louis and Paul, for making me aware of the papers which
I have read with much interest. ?I was aware of the detailed
work of David Morgan on VLF emissions from meteor
plasma (BAA RAG website) but not the perturbation of VLF propagation?by
ionisation trails. ?
?
In the earlier paper that you
referenced J-L you mentioned that video was also
included in the measurement approach. Did they capture
any of the events and provide meteor trajectory details
and how was the (very reasonable) ?that the meteor
appeared to have passed through a general line between
TX and RX.?
It appears that not only does one
need the meteor to be tangential to an ellipsoid with
foci at receiver and GRAVES ( the condition for for the
VHF specular trail of forward scatter) but also it is
bounded by the ellipsoids centred on receiver and VLF
transmitter. ?As with all meteor observations it depends
primarily on geometry.
It would seem that the observation
site would not only need to be in an optimal location
from the point-of-view of geometry but also in be
"quiet" electromagnetically. It would also, in my mind,
be the task for a dedicated station. (BAA funding??)
Finally J-L, did you have any
particular aspect of the phenomenon in mind with your
suggestion?
?
On 16
Mar 2021, at 10:54, Paul Hyde via groups.io <g4csd@...>
wrote:
?
As
Jean-Louis surmises, the SID VLF data would
not be suitable for investigating VLF
emissions from instabilities in meteor plasma
trails.? SIDs are of the order of tens of
minutes to hours and the timings collected in
observations reflect this.? If meteor-produced
VLF pings exist (being provocative here!) they
are more likely to be of the order of a
fraction of a second.
As
I understand it, there is statistical evidence
that the number of short duration VLF events
increases dramatically during meteor showers,
but it has been very difficult to distinguish
between a meteor-produced VLF spike and the
huge number created by other mechanisms,
lightning in particular.? Lightning storms in
Brazil (for example) generate VLF/ULF pulses
that travel around the world.
It's
a fascinating subject and I know that
Jean-Louis has done a lot of work here, see
A
challenging investigative exercise!
On
Tuesday, 16 March 2021, 09:02:19 GMT, Rault
Jean-L. <f6agr@...>
wrote:
Hi
John B.
Yes,
there is a SID data base available as
explained by John Cook.
However,
I wonder if it could be used to search
for meteor SID.
The
solar SID are "long duration" events (10
seconds or more) and the meteor SID are
"short duration" events (a few seconds
or less). So I wonder if the parameters
of the existing solar SIDS softwawares
(integration parameter) are well adapted
for detecting the metor SIDS
Jean-Louis
?
Le
15/03/2021 à 22:21, John Berman via
groups.io a écrit?:
Jean-Louis?
this sounds interesting, do we have a
SID database,
if not and we think there maybe some
mileage perhaps start a new topic and
let’s discuss
john B
Attachments:
|
