Many thanks to all for correcting me on the 'first ever' issue. I wasn't sure if stuff like this had happened in the past, so I appreciate folks setting me straight. Still a rare case and a hard problem for the students to work!
Also, many thanks to the folks in the UK for putting up such a useful educational bird. The students were intentionally not given all of the information about AO-73 and FO-29 and were told to do a 'Failure Analysis' to try to think about why the crosslink would fail. The intent was to get them to do some research and think outside the box a bit. I was very pleased when one team discovered the weekday/weekend operating schedule of the satellite and factored that into their simulation software (weaker beacon power on the weekends reduces the probability of a succesful TLM crosslink).
Great Stuff! Thanks to all!
-Zach, KJ4QLP
Research Associate Ted & Karyn Hume Center for National Security & Technology Virginia Polytechnic Institute & State University Work Phone: 540-231-4174 Cell Phone: 540-808-6305
On 5/7/2016 5:49 AM, Graham Shirville wrote:
Hi All,
Yes there is lots of history for DOHOP operations - for instance see ftp://www.amsat.org/amsat/news/1996/spc0401.txt
I can remember when the late G4CUO was very active over here.
Anyway we are always pleased to hear that the telemetry downlinks from FUNcube-1 are being used in novel ways.
73
Graham G3VZV
-----Original Message----- From: Alan Sent: Saturday, May 07, 2016 12:17 AM To: 'Zach Leffke' ; amsat-bb@amsat.org Subject: Re: [amsat-bb] AO-73 telemetry received via FO-29
Zach,
Probably the first telemetry relay, but not quite the first relay. I recall literally decades ago there was a relay, probably but not definitely from 70 cm to 2 m to 10 m. It might have included AO-7 in its first incarnation. Perhaps some of the really OTs might recall the details. Still, a great achievement. Especially calculating the hop to hop Doppler!
73s,
Alan WA4SCA
<-----Original Message----- <From: AMSAT-BB [mailto:amsat-bb-bounces@amsat.org] On Behalf Of Zach Leffke <Sent: Friday, May 06, 2016 5:36 PM <To: amsat-bb@amsat.org <Subject: Re: [amsat-bb] AO-73 telemetry received via FO-29 < <AHHHHHHHHHH........... < <you beat me to the punch!!!!!!!!!!!! < <We also received AO-73's signal via FO-29 today at the VTGS (we only got <6 packets!). < <We did this as part of a class project for ECE-4644 Satellite <Communications, and the students that were with me during the <observation of the event received a half letter grade bump on their <grade for the class project. The student project was to build a piece <of simulation software that would predict when the chain events between <the two birds would occur and to compute the doppler offset and link <budget in one second time steps for each event in a two week period. <I'm proud to say they not only predicted when the event would occur, <they were SPOT ON in the doppler computation (from around +5 kHz to <about +10kHz offset from center of FO-29's downlink here in Blacksburg VA). < < <Score for Amateur Radio supporting Students' Education! < <And Congratulations Paul! If I'm not mistaken, this is a first ever in <Amateur Radio satellite work, reception of a crosslink? Way to go! < <-Zach, KJ4QLP < <Research Associate <Ted & Karyn Hume Center for National Security & Technology <Virginia Polytechnic Institute & State University <Work Phone: 540-231-4174 <Cell Phone: 540-808-6305 < <On 5/6/2016 1:11 PM, Paul Stoetzer wrote: <> Good afternoon, <> <> I was able to decode 9 packets of telemetry from AO-73 via FO-29's <> transponder at 1647 UTC today. Signals were unusually strong as the <> satellites were close together, so I decided to try feeding my <> recording of the pass into the Dashboard. <> <> See an image of the Dashboard and a screenshot from SatPC32 showing <> where the two satellites were at the time here: <> <> https://twitter.com/PRStoetzer/status/728631296658944000 <> <> I was using just an Arrow antenna, High Sierra Microwave LNAA432 <> preamp, and an FT-817. <> <> 73, <> <> Paul, N8HM <> _______________________________________________ <> Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available <> to all interested persons worldwide without requiring membership. Opinions expressed <> are solely those of the author, and do not reflect the official views of AMSAT-NA. <> Not an AMSAT-NA member? Join now to support the amateur satellite program! <> Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb < <_______________________________________________ <Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available <to all interested persons worldwide without requiring membership. Opinions expressed <are solely those of the author, and do not reflect the official views of AMSAT-NA. <Not an AMSAT-NA member? Join now to support the amateur satellite program! <Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb
Sent via AMSAT-BB@amsat.org. AMSAT-NA makes this open forum available to all interested persons worldwide without requiring membership. Opinions expressed are solely those of the author, and do not reflect the official views of AMSAT-NA. Not an AMSAT-NA member? Join now to support the amateur satellite program! Subscription settings: http://www.amsat.org/mailman/listinfo/amsat-bb