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 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 out-of-date, though I think it would be a marginal thing.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 >>>>> >>>>> >>>> >>>> >>>> >>> >>> -- >>> --- >>> Roger J A Duthie >>> PhD Candidate >>> Plasma Group >>> Department of Space & Climate Physics >>> UCL, London >>> >>> w: +44(0)1483 204 100 ext 2299 >>> m: +44(0)7938 55 70 44 >>> >> > > -- > --- > Roger J A Duthie > PhD Candidate > Plasma Group > Department of Space & Climate Physics > UCL, London > > w: +44(0)1483 204 100 ext 2299 > m: +44(0)7938 55 70 44 _______________________________________________ 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
