Hi Roger et al The spectrogram attached for the 1310z Prospero pass today shows a carrier between 13:16 and 13:20 that matches the Prospero doppler profile (pretty well vertical), and exactly on 137.560MHz. There was some Orbcomm chuffing reasonably weak in the background, so it could be an Orbcomm satellite that exactly matched the doppler profile for Prospero. I couldnt hear anything significant in the audio. This was received with a non directional antenna. Do you have a similar spectrogram received with a beam antenna. If the signal wasn't there then we may assume it was from Orbcomm or similar in a different beam direction.
cheers all Tony Abbey - Senior Research Fellow (retired) Space Research Centre Dept of Physics and Astronomy University of Leicester University Road SRC Web page: http://www.src.le.ac.uk LEICESTER LE1 7RH, United Kingdom On 28 Oct 2011, at 10:25, Roger Duthie wrote: > OK - so that's definitely Orbcomm (from the spectrogram). Have you got audio > of this? > > We hear a chuffing sound intermittently (ie., it comes and goes in interval > of minutes), which happens when neither Orbcomm nor Prospero is reported by > our software to be above the horizon (is this the pager stuff you're talking > about?). We also heard another thing a couple of days ago, though we're > still not 100% on what that might have been (it appeared to be fading as > Prospero receded to the North - though was it an aeroplane on 137.56?). > > Someone yesterday has supposedly heard something that's wasn't Orbcomm during > the early evening pass. We'll look into it. > > The pass we're going to try today (for the sake of ceremony, really) is > (again, times in BST = UT + 1): > > 28 Oct 7.4 15:53:18 10 S 16:00:22 86 > W 16:08:28 10 N > - Roger > m0rja > > Tony Abbey wrote: >> >> Hi Roger >> >> Once Graham told me the noise was Orbcomm this morning, I added the TLEs for >> their satellites >> (http://www.orbcomm.com/Collateral/Documents/English-US/o11292.tle) >> to my SDR Radio software satellite definitions. Here's a pass I recorded >> from one of them this morning, and you can see that the "chuff-chuff" on the >> left hand side has structure which is kept vertical by the doppler >> correction. The other crap and pager cross talk etc bends with the doppler >> correction. I think that proves the point. >> >> Tony Abbey - Senior Research Fellow (retired) >> Space Research Centre >> Dept of Physics and Astronomy >> University of Leicester >> University Road SRC Web page: http://www.src.le.ac.uk >> LEICESTER LE1 7RH, United Kingdom >> Spectrogram removed by RJAD (might ahve been bad for the amsat-bb board) >> >> On 27 Oct 2011, at 16:17, Roger Duthie wrote: >> >>> We're hearing these 'chuff-chuff swooshes' too, though at times when our >>> software is not showing Orbcomm over our horizon. Our TLEs may be slightly >>> out-of-date, though I think it would be a marginal thing. Can it be >>> definitely confirmed that these noises are Orbcomm? >>> >>> - Rr. >>> >>> Tony Abbey wrote: >>>> >>>> Nothing heard from Prospero here in Leicester, that pass just finished (at >>>> 14:57Z) >>>> Just the Orbcomm swooshes. >>>> >>>> Tony Abbey - Senior Research Fellow (retired) >>>> Space Research Centre >>>> Dept of Physics and Astronomy >>>> University of Leicester >>>> University Road SRC Web page: http://www.src.le.ac.uk >>>> LEICESTER LE1 7RH, United Kingdom >>>> >>>> >>>> >>>> >>>> >>>> On 27 Oct 2011, at 13:33, Roger Duthie wrote: >>>> >>>>> Well, we're hearing something like that. Though we hear this a lot, we >>>>> also wonder whether we''re seeing an envelope during the Prospero pass >>>>> times. >>>>> >>>>> The passes for today (BST) [from Heavens-Above]: >>>>> 27 Oct 7.2 15:42:26 10 S 15:49:21 77 >>>>> E 15:57:21 10 NNE >>>>> 27 Oct 8.7 17:28:31 10 WSW 17:34:45 31 >>>>> WNW 17:41:39 10 N >>>>> Also, I've started a Twitter hashtag for anyone using this mode of >>>>> communication: #Prospero40 Add this to any Twitter messages you might >>>>> write about Prospero or related subjects. >>>>> >>>>> -Roger >>>>> >>>>> PE0SAT wrote: >>>>>> >>>>>> Hi, >>>>>> >>>>>> I have a spectrogram and a recording of that "chuff chuff" on >>>>>> http://www.pe0sat.vgnet.nl/satellite/sat-history/prospero/ >>>>>> >>>>>> Is it the same you guys heard? >>>>>> >>>>>> 73 Jan PE0SAT >>>>>> >>>>>> >>>>>> On Thu, October 27, 2011 10:04, g.shirvi...@btinternet.com wrote: >>>>>> >>>>>>> Hi Tony, >>>>>>> >>>>>>> The chuff chuff noises are from space...they are a sort of beacon >>>>>>> carried >>>>>>> on >>>>>>> every Orbcomm satellite. They are 125msec long pulses of 57.6kb data and >>>>>>> have a bandwidth of around 50kHz. They are quite distinctive when you >>>>>>> only >>>>>>> hear one at a time but sometimes one can hear two or more signals at the >>>>>>> same time and that sort of changes the sound:) >>>>>>> >>>>>>> 73 >>>>>>> >>>>>>> Graham >>>>>>> G3VZV >>>>>>> >>>>>>> -----Original Message----- >>>>>>> From: Tony Abbey >>>>>>> Sent: Wednesday, October 26, 2011 8:56 PM >>>>>>> To: r...@mssl.ucl.ac.uk >>>>>>> Cc: Phil Guttridge ; amsat-bb@amsat.org >>>>>>> Subject: [amsat-bb] Re: [Re: Prospero] Commanding Error >>>>>>> >>>>>>> Hi Roger >>>>>>> >>>>>>> Nothing other than the chuff- chuff on the 1600 pass. And as you said, >>>>>>> its >>>>>>> also there with Prospero over the horizon. I 'm not using a beam >>>>>>> presently >>>>>>> - >>>>>>> using a 360deg parasitic Lindenblad for circular polarisation, but it is >>>>>>> susceptible to all the high power pager stuff nearby. Its just strange >>>>>>> that >>>>>>> there are elements shifting in frequency in the chuff chuff like a >>>>>>> signal >>>>>>> from a real satellite. >>>>>>> Have just come back from a Rosat re-entry celebration! >>>>>>> >>>>>>> Tony Abbey - Senior Research Fellow (retired) >>>>>>> Space Research Centre >>>>>>> Dept of Physics and Astronomy >>>>>>> University of Leicester >>>>>>> University Road SRC Web page: http://www.src.le.ac.uk >>>>>>> LEICESTER LE1 7RH, United Kingdom >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> >>>>>>> On 26 Oct 2011, at 16:17, Roger Duthie wrote: >>>>>>> >>>>>>> >>>>>>>> Tony - >>>>>>>> >>>>>>>> We heard something intriguing after about 14:43:40 UT as the tracking >>>>>>>> said >>>>>>>> the satellite was on it's way off to the north pole. >>>>>>>> >>>>>>>> The 'chuff-chuff' description reminds me of a sound we seem to hear >>>>>>>> quite >>>>>>>> a lot. Quite often it coincides with a pass, though I think we hear >>>>>>>> the >>>>>>>> same (or very similar) during times when Prospero is over the horizon. >>>>>>>> >>>>>>>> We are going to try the next pass at ~16:00UT if you want to listen in >>>>>>>> again. Our new ploy is to wait for the last most opportune moment to >>>>>>>> command, as the power _may_ be at it highest (longest charging of >>>>>>>> batteries, potentially). So, we'll do short commanding at above 30o >>>>>>>> el, >>>>>>>> and listen. >>>>>>>> >>>>>>>> -Rr. >>>>>>>> >>>>>>>> Tony Abbey wrote: >>>>>>>> >>>>>>>>> Hi Roger >>>>>>>>> >>>>>>>>> I could hear some "chuff-chuff" noises on the last pass and they show >>>>>>>>> a >>>>>>>>> related doppler shift (although I am not correcting sufficiently) as >>>>>>>>> you >>>>>>>>> can see in the attached plot. Maybe its some other noise but you never >>>>>>>>> know. >>>>>>>>> >>>>>>>>> On 26 Oct 2011, at 13:39, Roger Duthie wrote: >>>>>>>>> >>>>>>>>>> Commanding went well, from as far as we could make out. We're not >>>>>>>>>> sure >>>>>>>>>> if we're getting anything back, however. >>>>>>>>>> >>>>>>>>>> We'll be doing this pass today, hopefully: >>>>>>>>>> >>>>>>>>>> 26 Oct 7.3 15:31:43 10 S 15:38:26 60 E 15:46:11 10 NNE [Times in BST >>>>>>>>>> = >>>>>>>>>> UTC + 1] >>>>>>>>>> >>>>>>>>>> -Roger >>>>>>>>>> >>>>>>> _______________________________________________ >>>>>>> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite >>>>>>> program! >>>>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>>>>>> >>>>>>> _______________________________________________ >>>>>>> Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. >>>>>>> Not an AMSAT-NA member? Join now to support the amateur satellite >>>>>>> program! >>>>>>> Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb >>>>>>> >>>>>>> _______________________________________________ Sent via AMSAT-BB@amsat.org. Opinions expressed are those of the author. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://amsat.org/mailman/listinfo/amsat-bb
