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
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 [email protected]. 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
That's all pretty cool! Congrats to Paul and the VT folks!
John KG4AKV On May 6, 2016 6:35 PM, "Zach Leffke" [email protected] wrote:
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 [email protected]. 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 [email protected]. 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
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:[email protected]] On Behalf Of Zach Leffke <Sent: Friday, May 06, 2016 5:36 PM <To: [email protected] <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 [email protected]. 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 [email protected]. 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
Alan,
Yes, there were hams talking through OSCARs 6 and 7 in the 1970s. I read about that in preparing for a 2015 presentation I gave to a non-ham crowd, talking about how hams have had a part in the Space Age. There was also PCSAT-2 on the ISS being retransmitted by PCSAT (NO-44) in 2005 and 2006 and then copied by ground stations, as documented by WB4APR at:
http://www.aprs.org/pec/pc2ops.html
I couldn't tell from that page how many times ground stations were retransmitted by both of those satellites, but that page shows how one satellite was heard by the other, and then the retransmission was heard on the ground.
Seeing Zach's explanation on how the calculations for Doppler were made, dealing with two different satellites, was impressive! Congratulations to Zach and his class, and also to Paul N8HM for also copying the AO-73 telemetry through FO-29.
73!
Patrick WD9EWK/VA7EWK http://www.wd9ewk.net/ Twitter: @WD9EWK
On Fri, May 6, 2016 at 11:17 PM, Alan [email protected] wrote:
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
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' ; [email protected] 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:[email protected]] On Behalf Of Zach Leffke <Sent: Friday, May 06, 2016 5:36 PM <To: [email protected] <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 [email protected]. 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 [email protected]. 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 [email protected]. 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
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' ; [email protected] 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:[email protected]] On Behalf Of Zach Leffke <Sent: Friday, May 06, 2016 5:36 PM <To: [email protected] <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 [email protected]. 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 [email protected]. 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 [email protected]. 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
participants (6)
-
Alan -
Graham Shirville -
John Brier -
Patrick STODDARD (WD9EWK/VA7EWK) -
Paul Stoetzer -
Zach Leffke