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PhotoGav

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Everything posted by PhotoGav

  1. The continuing story: I moved the aerial from the Warm Room to outside yesterday and the radio sky has exploded into life... and it was pretty busy before! I am finding that it is regularly detecting an almost continuous stream around events. Is this just lingering ionisation or might it be the direct GRAVES signal itself? I can't belief it is the direct signal as geography suggests that is not possible. My best interpretation is that the system is now massively more sensitive. I have reduced the Gain right down and altered the SNR threshold up slightly. I will see if that calms things down to just the more significant meteor events - though the first screenshot would suggest that that hasn't happened. Here are a selection of screenshots, including what I can only imagine is a pass of multiple Starlink satellites:
  2. Nice video, thanks for posting! That looks ultra easy with the ASA mount. I have a Mesu 200 and the software doesn’t have that balance feature. I have balanced as well as I could manually. Any ideas about a software solution for direct drive mounts other than the ASA?
  3. Looking through my data, I have found some more probable ISS events. This is a little earlier from the same 18-12-20, 12:40 pass: And one from the 07:50 pass this morning: And finally, a noisy one from the 13:27 pass yesterday 17-12-20: The ISS 'ugly' orbit is obviously just in the right patch of sky right now, so no doubt more events to come.
  4. @johnb - I think that I have just detected an ISS pass: That is certainly the strongest satellite signal that I have seen so far and there was a pass today from my location as follows: 12:36:48 W 10˚ -> 12:40:04 SSW 47˚ -> 12:43:19 SE 10˚ Please let me know if it would be useful for your project and if so, how to go about adding observations.
  5. Hi John, that is fascinating, well done for attempting the mapping project and for the excellent results so far. It seems that the meteors we detect with the GRAVES frequency here in the UK are generally occurring in the atmosphere above France somewhere, which are unlikely to be seen visually from southern England. Is that correct?
  6. Very interesting to see what others are capturing. Here is my heat map for December so far: And a few captures from last night: The system has been very busy and continues to be so. It will be interesting to see at what point it starts to calm down. It has been great to have a radio system in operation as the sky was pretty awful here last night. The Observatory where I work has a whole calendar of outreach events, including last night for the Geminids. Normally this would involve people meeting at the Dome to stand outside looking out for meteors. The event couldn't go ahead as normal this year due to Covid restrictions and would have been cancelled anyway due to the cloud, but thanks to the new system we were able to meet in a Zoom session, with over 30 participants enjoying the live feed from the radio meteor detector, watching the waterfall for pings and listening to the ssssshhssshhhhsssweeoooooshsshsssshhhsssweoossshhhssssweeeoooooshhhssssssss audio!
  7. @The Admiral, that’s great, thank you Ian. I’ve seen some of these documents, but not all. Plenty of research reading there. I agree, it’s not simple!
  8. Thank you @Geminids. No, there is no trajectory info from the all sky camera, though the meteor in the image above was a Leonid, so moving from east to west. Thank you for that link, I will enjoy reading and learning, there’s lots of good stuff there. I don’t know what the details are for the antenna I have - how would I find those things out?
  9. @Tomatobro & @wxsatuser - thank you both. I think I will give ‘no elevation’ a go and see how it fares while I make a bespoke bracket.
  10. Thank you, that is all interesting and helpful. Hopefully I might be able to contribute some useful data to the Radio Meteor Detection project in time, extending the contributor area in the south! On another question, if I may - does the angle of elevation of the aerial matter that much? I have another thread asking about this, but thought I would seize you while I have you! Is it ok if the aerial is level rather than raised to my theoretical optimum of 17°?
  11. Here’s a general question regarding the aerial: does the elevation angle of the aerial really matter? The theoretical elevation from my location is 17°, but if it is basically horizontal, will it make a significant difference? I am struggling to devise a good method of getting the 17° angle on the antenna when I am mounting the system outside on a big tripod and 3m mast. I bought an adjustable elevation bracket, but it is a bit flimsy and I don’t have the correct hardware to attach the aerial to it anyway! I’m wondering if I can not worry about this 17° angle for now and still get good data?
  12. I like that idea very much, thank you! You might have seen that I have also started another thread about decoding the waterfall to understand what the reflections tell us about the meteors that caused them. Your thoughts would be most welcome!
  13. Good stuff, thank you. I thought that was the case. It will be interesting to catch the ISS passing by one day! Ah, interesting, thank you. I thought that Doppler shift was correlated to frequency change, dropping in Hz as the meteor slows down in the atmosphere, hence the events with the ‘tails’ moving down the waterfall and the bright blob at the end. So much to learn!
  14. As the title suggests, I would like to try and understand what the waterfall display of GRAVES reflections can tell me about the meteor that caused it. Or was it even a meteor...??! Here are a number of event screen shots. These are the 'normal' ones - what do the various shapes, durations and brightnesses say about the meteors? And then some weirder ones: I look forward to hearing how to identify the 'reflection zoo'!! Finally, is it appropriate to correlate these two as being the same meteor? Thanks, Gav.
  15. My next questions are going to be all about what the waterfall display tells us... pictures and questions to follow soon!
  16. Mike, thank you so much for this suggestion. I attempted to tune to the GB3VHF signal today and it appeared straight away, loud and clear! I tweaked the ppm setting to bring it to the 144.430MHz indicator in SDR# and the GRAVES pings are now appearing at 2000 Hz when the dongle is tuned to 143.048MHz. Here's a screen shot: Next step is to get the aerial installed permanently outside, just waiting for an altitude adjustable mast bracket, which is arriving tomorrow. I should then be ready for the Geminids! Thank you for your help. Gav.
  17. Looking at the GB3VHF website, there is a report from a user in Chippenham, which is further west than me, so I’m feeling confident! Will give it a go when I’m up at the Observatory next.
  18. That’s very helpful, thank you Mike. So if I point the aerial towards Wrotham (basically east from where I am), I should be able to pick up that signal, hopefully?
  19. Hi John, sorry, I missed this message during the week. Thank you for the contact. I have just moved the whole system to the Observatory this afternoon where it will be properly installed (eventually) and the airwaves already seem to be much clearer. The aerial is still indoors (in the Obsy warm room), but it's nice and isolated up there. I will move it outdoors once I have a reliable system to fix it down! This is the aerial in its new home: It seems to be capturing much better 'pings'. Here is an example: and its associated audio file: event20201128_151559_11.wav Here's another ping, or is it?? and the audio: event20201128_154137_16.wav What do you reckon to that event? Everything is still being registered at 2300 Hz above 143048000, which is 300 Hz higher than the GRAVES signal. I think that the Funcube dongle must be slightly out with its tuning numbers. I see that there is a setting to make a global alteration to account for this, but I need a single test frequency to lock on to and make the adjustment. Do you know of a suitable frequency that I could use? All in all, I think that the system is working quite well now and I look forward to seeing what it captures over the next few days and nights. Thanks, Gav.
  20. I don't know what it should sound like, but from what I've heard so far, it isn't that odd! As for it being off frequency - all the 'meteor events' it is recording are pretty much at that frequency, give or take. I presumed that the dongle is just slightly off and I haven't plugged in an offset value yet - is that fair?
  21. I used the @johnb settings file (thank you John!), modified it slightly for my set up and let it run through the night. Here is an example of what I have found this morning: event20201108_064441_3.wav WARNING - the wav file is quite loud! Things seem to be working nicely now. Thank you @johnb for your help. The system only captured three screenshots through the night, so I guess it was pretty quiet on the meteor front. It did save quite a few wav files, but listening to them there doesn't seem to be anything relevant in the majority of them. Lots more tinkering to do to get this all working perfectly, but it's rather exciting to be detecting meteor reflections already!
  22. @johnb - fabulous, thank you for the .usr file and for the link to that excellent thread. I will try loading your usr file and see how it goes. Thank you!
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