Hi Roger The email list increases exponentially;-) I saw Jan's post with audio links. So just for completeness here's a file from the same spectrogram I posted yesterday, starting at around 09:33. The chuffs get quite loud and sometimes there's a double chuff, which I understand maybe from two Orbcomm sats.
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, [email protected] 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: [email protected] >>>>>>> Cc: Phil Guttridge ; [email protected] >>>>>>> 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 [email protected]. 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 [email protected]. 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 [email protected]. 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
