[amsat-bb] AO-73 telemetry received via FO-29

[Zach Leffke]

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 at 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 at amsat.org] On Behalf Of Zach 
> Leffke
> <Sent: Friday, May 06, 2016 5:36 PM
> <To: amsat-bb at 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
> <> _______________________________________________
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> <_______________________________________________
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>
> _______________________________________________
> Sent via AMSAT-BB at 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!
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