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Re: Successful detection and velocity calculation for galactic hydrogen using phased array
开云体育Hi Wolfgang, Any chance we could speak privately about how to reduce my data? I understand you are expert on this! Andy ? From: [email protected] <[email protected]>
On Behalf Of Andrew Thornett via groups.io
Sent: 29 September 2023 23:41 To: [email protected] Subject: Re: [baa-rag] Successful detection and velocity calculation for galactic hydrogen using phased array ? Thanks Wolfgang? ? Sent from From:
[email protected] <[email protected]> on behalf of messbetrieb via groups.io <messbetrieb@...> ? Andy, Here are a couple of comments: It would be helpful to know the characteristics of your antenna. Is there any technical documentation available which would give some numbers such as opening angle / gain? Looking at the picture of the antenna is seems that the various elements are internally connected to provide a single port, so the antenna has a? fixed pattern. There may be one disadvantage: Since the coupling elements will inevitably have some loss, this adds noise. For terrestrial applications for which the antenna was intended, this will not matter too much as the antenna will pick up thermal noise from the ground anyway. For astronomical applications, however, this may be a disadvantage. Without knowing more details it is not possible to assess how much on an issue this might be. The next thing I noticed is that you have a cable of maybe 1m length between the antenna port and the LNA. It would be better to have the LNA directly at the antenna port. The attenuation of the cable will introduce noise which can be avoided. I assume your spectra were taken with the antenna pointing straight upwards. It would be helpful to know the coordinates of your location and the time when the recording was taken in order to determine the sky location where you were pointing. If I interpret correctly your recording taken with ezRA, you have been recording at 1420 MHz with 2.6 MHz bandwidth and then displayed the total power in that band over time. In that case you would have received emission from hydrogen plus a small contribution from the synchrotron radiation in the galactic plane. With small antennas you can only expect to see the hydrogen emission. In this case, it would be better to narrow the bandwidth to the range of the hydrogen spectrum to increase you SNR. 500 kHz around 11420.4 MHz would be a good starting point. I don’t think you have actually as signal from the galactic plane in your plot. As far as your signal at 1419.6 MHz is concerned, this would correspond to a redshift of ~ 170 km/s if it were hydrogen (you seem to have done something wrong in your calculation). ?Such velocities do not occur in our galaxy, so this must be something else (or there was something weird with the frequency setting of your SDR). ? ? Best regards, Wolfgang ? Von:
[email protected] <[email protected]>
Im Auftrag von Andrew Thornett via groups.io ? I have summarised my progress so fsr on my website on URL below. ?
? Please can you take a look - I am really keen to receive constructive comments and criticisms to help me improve the observations and also suggestions for what I do next..I would like to try to map the Milky Way but not sure best way to go about this? ? Andy ? ? ? ? |
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Re: Successful detection and velocity calculation for galactic hydrogen using phased array
开云体育Please see I am quite excited! Thanks to Ted Cline from SARA for his marvelous ezRA software and wonderfully supportive help to achieve this. Andy ? ? From: [email protected] <[email protected]>
On Behalf Of Andrew Thornett via groups.io
Sent: 29 September 2023 23:41 To: [email protected] Subject: Re: [baa-rag] Successful detection and velocity calculation for galactic hydrogen using phased array ? Thanks Wolfgang? ? Sent from From:
[email protected] <[email protected]> on behalf of messbetrieb via groups.io <messbetrieb@...> ? Andy, Here are a couple of comments: It would be helpful to know the characteristics of your antenna. Is there any technical documentation available which would give some numbers such as opening angle / gain? Looking at the picture of the antenna is seems that the various elements are internally connected to provide a single port, so the antenna has a? fixed pattern. There may be one disadvantage: Since the coupling elements will inevitably have some loss, this adds noise. For terrestrial applications for which the antenna was intended, this will not matter too much as the antenna will pick up thermal noise from the ground anyway. For astronomical applications, however, this may be a disadvantage. Without knowing more details it is not possible to assess how much on an issue this might be. The next thing I noticed is that you have a cable of maybe 1m length between the antenna port and the LNA. It would be better to have the LNA directly at the antenna port. The attenuation of the cable will introduce noise which can be avoided. I assume your spectra were taken with the antenna pointing straight upwards. It would be helpful to know the coordinates of your location and the time when the recording was taken in order to determine the sky location where you were pointing. If I interpret correctly your recording taken with ezRA, you have been recording at 1420 MHz with 2.6 MHz bandwidth and then displayed the total power in that band over time. In that case you would have received emission from hydrogen plus a small contribution from the synchrotron radiation in the galactic plane. With small antennas you can only expect to see the hydrogen emission. In this case, it would be better to narrow the bandwidth to the range of the hydrogen spectrum to increase you SNR. 500 kHz around 11420.4 MHz would be a good starting point. I don’t think you have actually as signal from the galactic plane in your plot. As far as your signal at 1419.6 MHz is concerned, this would correspond to a redshift of ~ 170 km/s if it were hydrogen (you seem to have done something wrong in your calculation). ?Such velocities do not occur in our galaxy, so this must be something else (or there was something weird with the frequency setting of your SDR). ? ? Best regards, Wolfgang ? Von:
[email protected] <[email protected]>
Im Auftrag von Andrew Thornett via groups.io ? I have summarised my progress so fsr on my website on URL below. ?
? Please can you take a look - I am really keen to receive constructive comments and criticisms to help me improve the observations and also suggestions for what I do next..I would like to try to map the Milky Way but not sure best way to go about this? ? Andy ? ? ? ? |
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Re: History of Jodrell Bank
Hi Mark I've put it in my diary. I see your talk is not listed in the Newcomen Society event calendar. Tony On Mon, 2 Oct 2023 at 14:32, Mark Edwards <mark@...> wrote:
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History of Jodrell Bank
开云体育If anyone is interested I am giving a talk on the early history of Jodrell Bank at the Newcomen Society in Brum on 1st November - see attached flyer. ? Mark ? |
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Detection hydrogen using Phased Array and SDR# with IFAverage Plug in and processed using ezRA suite
开云体育At last! Pretty sure I have now managed to transfer my data to ezRA suite to produce some nifty plots! Waiting for Ted Cline from SARA to confirm – but it seems to me likely the following show hydrogen. As always comments and constructive criticisms are very welcome! I am hoping to let this run for few days and then demonstrate varying plot over time. Andy ? From last night: ? The following shows the typical double peak of hydrogen detected via SDR# with IFAverage Plug-in and 50 Ohm dummy load to calibrate: ? ? When I processed the data from last night from SDR# IFAverage plug-in is processed in ezRA suite, I obtained following results: ? ? The Doppler shift of -0.4MHz corresponds to the hydrogen peaks seen on SDR# on same system – so even if the Doppler shift itself is erroneous due to some error in system then this data above corresponds to the typical hydrogen trace. In addition, this peak is +96 degrees galactic longitude which corresponds to when Cygnus crossed Zenith – my Ptarmigan Triffid array is pointed at the Zenith. ? The peak drops gradually as galactic longitude moves away from +96 degrees so that at +91 degrees see below: ? ? There is another peak at +152 degrees galactic longitude, smaller than peak above = the Milky Way was now crossing Perseus: ? ? The above findings correspond to the bright orange strip in the plot below: ? ? ? |
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Re: Successful detection and velocity calculation for galactic hydrogen using phased array
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From: [email protected] <[email protected]> on behalf of messbetrieb via groups.io <messbetrieb@...>
Sent: Friday, September 29, 2023 9:22:38 PM To: [email protected] <[email protected]> Subject: Re: [baa-rag] Successful detection and velocity calculation for galactic hydrogen using phased array ?
Andy, Here are a couple of comments: It would be helpful to know the characteristics of your antenna. Is there any technical documentation available which would give some numbers such as opening angle / gain? Looking at the picture of the antenna is seems that the various elements are internally connected to provide a single port, so the antenna has a? fixed pattern. There may be one disadvantage: Since the coupling elements will inevitably have some loss, this adds noise. For terrestrial applications for which the antenna was intended, this will not matter too much as the antenna will pick up thermal noise from the ground anyway. For astronomical applications, however, this may be a disadvantage. Without knowing more details it is not possible to assess how much on an issue this might be. The next thing I noticed is that you have a cable of maybe 1m length between the antenna port and the LNA. It would be better to have the LNA directly at the antenna port. The attenuation of the cable will introduce noise which can be avoided. I assume your spectra were taken with the antenna pointing straight upwards. It would be helpful to know the coordinates of your location and the time when the recording was taken in order to determine the sky location where you were pointing. If I interpret correctly your recording taken with ezRA, you have been recording at 1420 MHz with 2.6 MHz bandwidth and then displayed the total power in that band over time. In that case you would have received emission from hydrogen plus a small contribution from the synchrotron radiation in the galactic plane. With small antennas you can only expect to see the hydrogen emission. In this case, it would be better to narrow the bandwidth to the range of the hydrogen spectrum to increase you SNR. 500 kHz around 11420.4 MHz would be a good starting point. I don’t think you have actually as signal from the galactic plane in your plot. As far as your signal at 1419.6 MHz is concerned, this would correspond to a redshift of ~ 170 km/s if it were hydrogen (you seem to have done something wrong in your calculation). ?Such velocities do not occur in our galaxy, so this must be something else (or there was something weird with the frequency setting of your SDR). ? ? Best regards, Wolfgang ? Von: [email protected] <[email protected]> Im Auftrag von
Andrew Thornett via groups.io ? I have summarised my progress so fsr on my website on URL below. ? ? Please can you take a look - I am really keen to receive constructive comments and criticisms to help me improve the observations and also suggestions for what I do next..I would like to try to map the Milky Way but not sure best way to go about this? ? Andy ? ? ? ? |
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Re: Successful detection and velocity calculation for galactic hydrogen using phased array
开云体育Andy, Here are a couple of comments: It would be helpful to know the characteristics of your antenna. Is there any technical documentation available which would give some numbers such as opening angle / gain? Looking at the picture of the antenna is seems that the various elements are internally connected to provide a single port, so the antenna has a? fixed pattern. There may be one disadvantage: Since the coupling elements will inevitably have some loss, this adds noise. For terrestrial applications for which the antenna was intended, this will not matter too much as the antenna will pick up thermal noise from the ground anyway. For astronomical applications, however, this may be a disadvantage. Without knowing more details it is not possible to assess how much on an issue this might be. The next thing I noticed is that you have a cable of maybe 1m length between the antenna port and the LNA. It would be better to have the LNA directly at the antenna port. The attenuation of the cable will introduce noise which can be avoided. I assume your spectra were taken with the antenna pointing straight upwards. It would be helpful to know the coordinates of your location and the time when the recording was taken in order to determine the sky location where you were pointing. If I interpret correctly your recording taken with ezRA, you have been recording at 1420 MHz with 2.6 MHz bandwidth and then displayed the total power in that band over time. In that case you would have received emission from hydrogen plus a small contribution from the synchrotron radiation in the galactic plane. With small antennas you can only expect to see the hydrogen emission. In this case, it would be better to narrow the bandwidth to the range of the hydrogen spectrum to increase you SNR. 500 kHz around 11420.4 MHz would be a good starting point. I don’t think you have actually as signal from the galactic plane in your plot. As far as your signal at 1419.6 MHz is concerned, this would correspond to a redshift of ~ 170 km/s if it were hydrogen (you seem to have done something wrong in your calculation). ?Such velocities do not occur in our galaxy, so this must be something else (or there was something weird with the frequency setting of your SDR). ? ? Best regards, Wolfgang ? Von: [email protected] <[email protected]> Im Auftrag von Andrew Thornett via groups.io ? I have summarised my progress so fsr on my website on URL below. ? ? Please can you take a look - I am really keen to receive constructive comments and criticisms to help me improve the observations and also suggestions for what I do next..I would like to try to map the Milky Way but not sure best way to go about this? ? Andy ? ? ? ? |
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育RTL-SDR Blog V3 TOP3M9037-LNA pre-amp SAWbird-H1 cascaded pre-amp and 1420MHz filter ? ? From: [email protected] <[email protected]>
On Behalf Of Martyn Kinder via groups.io
Sent: 29 September 2023 14:34 To: [email protected] Subject: Re: [baa-rag] Success detecting galactic molecular hydrogen! (I can't believe it!) ? Well done Andrew.? |
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Successful detection and velocity calculation for galactic hydrogen using phased array
开云体育I have summarised my progress so fsr on my website on URL below.
Please can you take a look - I am really keen to receive constructive comments and criticisms to help me improve the observations and also suggestions for what I do next..I would like to try to map the Milky Way but not sure best way to go about
this?
Andy
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RAZoom is back - Fri. Oct. 6th 19:30BST
Dr. Asayama, Shinichiro?
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育Hi Andy, Our software for doing longer term recording is probably of no use for you as it communicates with our telescope control system. However, I would think that Ted Cline’s software would be a good fit for you: There are also a couple of videos he has created on how to use ezRA. You can find it at Good luck, Wolfgang ? ? Von: [email protected] <[email protected]> Im Auftrag von Andrew Thornett via groups.io ? Thanks Wolfgang. What software do you use to record atomic hydrogen (sorry about that mistake thanks for correcting me) over time so that it can be processed to display the distribution in the Galaxy on a graph? Andy ? Sent from From: [email protected] <[email protected]> on behalf of messbetrieb via groups.io <messbetrieb@...>
Sent: Monday, September 25, 2023 7:37:51 PM To: [email protected] <[email protected]> Subject: Re: [baa-rag] Success detecting galactic molecular hydrogen! (I can't believe it!) ? Hi Andy, When you point straight up you will collect data for one declination only, it will be the same every day. So you will need to change position of your antenna. Same comment as in the other forum: You are observing emission from atomic hydrogen, not molecular hydrogen. Good luck with your observations, Wolfgang ? ? Von: [email protected] <[email protected]> Im Auftrag von Andrew Thornett via groups.io ? Can I ask what members of this group think is best way to record and display my data? I am hoping to collect data over 1 year. Do I need to vary position of array or would pointing straight up for the whole year be adequate to obtain spectra from large part of Milky Way? Andy ? From: [email protected] <[email protected]> On Behalf Of Andrew Thornett via groups.io ? Hi All, Wow! Success 2 days ago with Triffid array and SDR.- successfully detected galactic hydrogen as per attached radio spectrum.?I am actually quite shocked as I am not used to my radio astronomy experiments working!! (Only just managed to get meteor detection from Graves working after about 5 years!) – and this was achieved within 2 weeks of starting data collection on this project which is truly amazing for me. However, I really need to give all the credit to Andy Thomas from this group, who generously gave me his Pharmigan Triffid military phased array. This is a wonderful piece of kit: (i)??????????? Seems to work MUCH better than similarly sized satellite dish on 1420MHz. (ii)?????????? Has better sky resolution than similarly sized dish. (iii)????????? My wife is happy with the look, whereas she can’t stand a dish, and has (incredibly) given me permission to mount the aerial on the patio long term (which I still can’t believe). (iv)????????? Everything thinks the horizontally mounted array looks like a BB, and hence fits in to the garden more easily. (v)?????????? ? Andy ? Attachments: |
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育Thanks Wolfgang. What software do you use to record atomic hydrogen (sorry about that mistake thanks for correcting me) over time so that it can be processed to display the distribution in the Galaxy on a graph?
Andy
Sent from From: [email protected] <[email protected]> on behalf of messbetrieb via groups.io <messbetrieb@...>
Sent: Monday, September 25, 2023 7:37:51 PM To: [email protected] <[email protected]> Subject: Re: [baa-rag] Success detecting galactic molecular hydrogen! (I can't believe it!) ?
Hi Andy, When you point straight up you will collect data for one declination only, it will be the same every day. So you will need to change position of your antenna. Same comment as in the other forum: You are observing emission from atomic hydrogen, not molecular hydrogen. Good luck with your observations, Wolfgang ? ? Von: [email protected] <[email protected]> Im Auftrag von
Andrew Thornett via groups.io ? Can I ask what members of this group think is best way to record and display my data? I am hoping to collect data over 1 year. Do I need to vary position of array or would pointing straight up for the whole year be adequate to obtain spectra from large part of Milky Way? Andy ? From:
[email protected] <[email protected]>
On Behalf Of Andrew Thornett via groups.io ? Hi All, Wow! Success 2 days ago with Triffid array and SDR.- successfully detected galactic hydrogen as per attached radio spectrum.?I am actually quite shocked as I am not used to my radio astronomy experiments working!! (Only just managed to get meteor detection from Graves working after about 5 years!) – and this was achieved within 2 weeks of starting data collection on this project which is truly amazing for me. However, I really need to give all the credit to Andy Thomas from this group, who generously gave me his Pharmigan Triffid military phased array. This is a wonderful piece of kit: (i)??????????? Seems to work MUCH better than similarly sized satellite dish on 1420MHz. (ii)?????????? Has better sky resolution than similarly sized dish. (iii)????????? My wife is happy with the look, whereas she can’t stand a dish, and has (incredibly) given me permission to mount the aerial on the patio long term (which I still can’t believe). (iv)????????? Everything thinks the horizontally mounted array looks like a BB, and hence fits in to the garden more easily. (v)?????????? ? Andy ? Attachments:
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育Hi Andy, When you point straight up you will collect data for one declination only, it will be the same every day. So you will need to change position of your antenna. Same comment as in the other forum: You are observing emission from atomic hydrogen, not molecular hydrogen. Good luck with your observations, Wolfgang ? ? Von: [email protected] <[email protected]> Im Auftrag von Andrew Thornett via groups.io ? Can I ask what members of this group think is best way to record and display my data? I am hoping to collect data over 1 year. Do I need to vary position of array or would pointing straight up for the whole year be adequate to obtain spectra from large part of Milky Way? Andy ? From: [email protected] <[email protected]> On Behalf Of Andrew Thornett via groups.io
Sent: 24 September 2023 10:04 To: [email protected] Subject: [baa-rag] Success detecting galactic molecular hydrogen! (I can't believe it!) ? Hi All, Wow! Success 2 days ago with Triffid array and SDR.- successfully detected galactic hydrogen as per attached radio spectrum.?I am actually quite shocked as I am not used to my radio astronomy experiments working!! (Only just managed to get meteor detection from Graves working after about 5 years!) – and this was achieved within 2 weeks of starting data collection on this project which is truly amazing for me. However, I really need to give all the credit to Andy Thomas from this group, who generously gave me his Pharmigan Triffid military phased array. This is a wonderful piece of kit: (i)??????????? Seems to work MUCH better than similarly sized satellite dish on 1420MHz. (ii)?????????? Has better sky resolution than similarly sized dish. (iii)????????? My wife is happy with the look, whereas she can’t stand a dish, and has (incredibly) given me permission to mount the aerial on the patio long term (which I still can’t believe). (iv)????????? Everything thinks the horizontally mounted array looks like a BB, and hence fits in to the garden more easily. (v)?????????? ? Andy ? Attachments:
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
toggle quoted message
Show quoted text
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Re: Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育Can I ask what members of this group think is best way to record and display my data? I am hoping to collect data over 1 year. Do I need to vary position of array or would pointing straight up for the whole year be adequate to obtain spectra from large part of Milky Way? Andy ? From: [email protected] <[email protected]>
On Behalf Of Andrew Thornett via groups.io
Sent: 24 September 2023 10:04 To: [email protected] Subject: [baa-rag] Success detecting galactic molecular hydrogen! (I can't believe it!) ? Hi All, Wow! Success 2 days ago with Triffid array and SDR.- successfully detected galactic hydrogen as per attached radio spectrum.?I am actually quite shocked as I am not used to my radio astronomy experiments working!! (Only just managed to get meteor detection from Graves working after about 5 years!) – and this was achieved within 2 weeks of starting data collection on this project which is truly amazing for me. However, I really need to give all the credit to Andy Thomas from this group, who generously gave me his Pharmigan Triffid military phased array. This is a wonderful piece of kit: (i)?????????????? Seems to work MUCH better than similarly sized satellite dish on 1420MHz. (ii)????????????? Has better sky resolution than similarly sized dish. (iii)???????????? My wife is happy with the look, whereas she can’t stand a dish, and has (incredibly) given me permission to mount the aerial on the patio long term (which I still can’t believe). (iv)???????????? Everything thinks the horizontally mounted array looks like a BB, and hence fits in to the garden more easily. (v)????????????? ? Andy ? Attachments:
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Success detecting galactic molecular hydrogen! (I can't believe it!)
开云体育Hi All, Wow! Success 2 days ago with Triffid array and SDR.- successfully detected galactic hydrogen as per attached radio spectrum.?I am actually quite shocked as I am not used to my radio astronomy experiments working!! (Only just managed to get meteor detection from Graves working after about 5 years!) – and this was achieved within 2 weeks of starting data collection on this project which is truly amazing for me. However, I really need to give all the credit to Andy Thomas from this group, who generously gave me his Pharmigan Triffid military phased array. This is a wonderful piece of kit: (i)?????????????? Seems to work MUCH better than similarly sized satellite dish on 1420MHz. (ii)????????????? Has better sky resolution than similarly sized dish. (iii)???????????? My wife is happy with the look, whereas she can’t stand a dish, and has (incredibly) given me permission to mount the aerial on the patio long term (which I still can’t believe). (iv)???????????? Everything thinks the horizontally mounted array looks like a BB, and hence fits in to the garden more easily. (v)????????????? ? Andy ? 
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Paul Hearn