[amsat-bb] AO-92 High Speed Data decode questions

Loren M. Lang penguin359 at gmail.com
Wed Apr 29 06:13:33 UTC 2020

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

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

I still have the original raw IQ capture from the event today.

- Loren

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