Interesting My observations last weekend show that MET matches the satellite entering sunlight: 18 September calculated Time into sun: 1004 utc Time of obs (announcement): 1023 utc Voice announced MET: 19 calculated Time into sun: 1136 utc Time of obs: 1158 utc Voice announced MET: 21 maybe the voice tlm MET isn't accurate either! howver I calculated the time of the entering sunlight using the keps of 24/9, not the keps of 18/9, via satpc32. 73 de andy g0sfj
From: Greg D. <[email protected]> To: andy thomas <[email protected]>; amsat <[email protected]> Sent: Saturday, 24 September 2011, 17:46 Subject: RE: [amsat-bb] Re: ARISSat daylightpower recovery time Based on posted observations, I have come to the conclusion that the satellite's MET comes up at either 0 or 1 when the satellite turns on, after the 10-or-so minute delay after entering sunlight. Depending on what mode it thinks it should be in, I suppose it's possible that it might in fact be in one of those power saving quiet periods at that time, and only be heard a few minutes later. Entering sunlight is not a knife-edged event in orbit; there's a short ramp in power, so (playing arm-chair engineer here) I expect it would be in low or emergency power mode for a short while. Greg KO6TH > Date: Sat, 24 Sep 2011 11:49:36 +0100 > From: [email protected] > To: [email protected] > Subject: [amsat-bb] Re: ARISSat daylightpower recovery time > > Did not catch the second voice digit! "MET is One shhhhhh" But satellite is > switched on. > > On 18 september the voice announced MET (19 and 21) equalled the time in > sunlight, as I have calculated back using today's keps, within 1 minute. > Allowing for keps 1 week old I think the MET is in fact announcing the time > the satellite "wakes up" as she enters sunlight, but there are no fm > transmissions at that time. The latency is up to 10 -19 minutes (if I had the > second digit I could be more precise,hi!!) > > From: andy thomas <[email protected]> > To: amsat <[email protected]> > Sent: Saturday, 24 September 2011, 11:24 > Subject: Re:ARISSat daylightpower recovery time > > > I agree with this observation here at IO92NL. > > Arissat-1 does not switch on immediately when in sunlight, I have missed > several passes this morning and in the last few days. > > I am just waiting for what the MET is announced (voice tlm) as at 1032 utc > AOS (coming up) and will backtrack to how long she has been in sunlight. The > difference ought to tell us the latency. > > 73 de andy G0SFJ > _______________________________________________ > 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
