AO-92 High Speed Data decode questions
I tried capturing some of the high-speed data from AO-92 today from the final 1750Z pass today when the camera was activated. I believe I had some success, but I am a little confused about what I captured. I did it in two stages using my phone to capture the raw IQ from my SDR during the pass and then playing it back on my computer right after into Foxtelem 108z5. The pass was only 16 degrees at it's peak, but I was able to hear the satellite down to as little as 6 degrees and Foxtelem reported 24 frames successfully decoded.
My first point of confusion is I heard QSO what sounded like modem sounds over the FM downlink intermixed with amateur calls coming through. I assume that was the high-speed 9600 data mode I was hearing, but this was starting a few minutes before 1750Z so was the camera mode able to be activated a little early? Second, is the repeater still active while HS mode is running? I thought that repeater operation would be disabled to avoid having voice interfering with the data downlink or is this not an issue?
Last question is, why do I not having anything under the Camera (1D) tab for AO-92? That tab is completely blank and doesn't seem to have any data collected. It appears that all frames received are under either the Health tab or HERCI HK (1D). The recent telemetry for HERCI HK is also all zeros it seems.
It definitely sounded like there was some high-speed data transfer happening, something besides the 200 bps DUV signal, but it doesn't look like I collected anything particular to the Camera operation. Was it not active during that time or did I just not collect enough frames to assemble anything?
I still have the original raw IQ capture from the event today.
- Loren K7IW
What you heard was the command station attempting to send the command to AO-92 to activate the camera.
Unfortunately, there were several stations trying to use the repeater at the time and blocking the commands being sent to AO-92.
When the camera is active, the repeater is not available.
Glenn AA5PK
-----Original Message----- From: Loren M. Lang via AMSAT-BB Sent: Wednesday, April 29, 2020 1:13 AM To: AMSAT BB Subject: [amsat-bb] AO-92 High Speed Data decode questions
I tried capturing some of the high-speed data from AO-92 today from the final 1750Z pass today when the camera was activated. I believe I had some success, but I am a little confused about what I captured. I did it in two stages using my phone to capture the raw IQ from my SDR during the pass and then playing it back on my computer right after into Foxtelem 108z5. The pass was only 16 degrees at it's peak, but I was able to hear the satellite down to as little as 6 degrees and Foxtelem reported 24 frames successfully decoded.
Ok, that makes sense. So the repeated signal I heard was simply repeated attempts at getting the command through and were being interfered with by the existing FM transmissions. All of the frames I collected would have actually been DUV and not the same as the sounds I heard. Did camera mode ever get activated during that third pass?
On Wed, Apr 29, 2020, 02:31 Glenn Miller - AA5PK [email protected] wrote:
What you heard was the command station attempting to send the command to AO-92 to activate the camera.
Unfortunately, there were several stations trying to use the repeater at the time and blocking the commands being sent to AO-92.
When the camera is active, the repeater is not available.
Glenn AA5PK
-----Original Message----- From: Loren M. Lang via AMSAT-BB Sent: Wednesday, April 29, 2020 1:13 AM To: AMSAT BB Subject: [amsat-bb] AO-92 High Speed Data decode questions
I tried capturing some of the high-speed data from AO-92 today from the final 1750Z pass today when the camera was activated. I believe I had some success, but I am a little confused about what I captured. I did it in two stages using my phone to capture the raw IQ from my SDR during the pass and then playing it back on my computer right after into Foxtelem 108z5. The pass was only 16 degrees at it's peak, but I was able to hear the satellite down to as little as 6 degrees and Foxtelem reported 24 frames successfully decoded.
No, it didn't get activated the third pass.
73, Drew KO4MA
-----Original Message----- From: AMSAT-BB [email protected] On Behalf Of Loren M. Lang via AMSAT-BB Sent: Wednesday, April 29, 2020 9:54 AM To: Glenn Miller - AA5PK [email protected] Cc: AMSAT BB [email protected] Subject: Re: [amsat-bb] AO-92 High Speed Data decode questions
Ok, that makes sense. So the repeated signal I heard was simply repeated attempts at getting the command through and were being interfered with by the existing FM transmissions. All of the frames I collected would have actually been DUV and not the same as the sounds I heard. Did camera mode ever get activated during that third pass?
Loren,
It is true that the DUV telemetry would continue uninterrupted, as long as AO-92 was still in Transponder Mode. As Drew confirmed the sat never made it to Data Mode (the mode that enables the camera and high speed data downlink) and if it had, the same DUV telemetry frames also come down in the high speed data so you would continue to see them on FoxTelem.
Jerry Buxton, NØJY
On 4/29/2020 08:53, Loren M. Lang via AMSAT-BB wrote:
All of the frames I collected would have actually been DUV and not the same as the sounds I heard. Did camera mode ever get activated during that third pass?
participants (4)
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Andrew Glasbrenner -
Glenn Miller - AA5PK -
Jerry Buxton -
Loren M. Lang