JY1Sat (43803) — Telemetry Documentation / Protocol Details

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Hello @bali,

I’m working on a decoder for telemetry transmitted by JY1Sat (43803) and am currently trying to understand and document its telemetry format.

I’ve been analyzing observations available through the SatNOGS database and have managed to extract and reconstruct valid telemetry frames from the received data. From this analysis, I’ve also been able to identify parts of the frame structure and decode a number of parameters, including values related to battery voltage, bus voltage, and system counters.

Before I go much further, I’d like to verify that the interpretations I’m making are actually correct rather than relying entirely on reverse-engineering.

Is there an official telemetry document, protocol description, or technical specification available for JY1Sat that describes the frame layout, telemetry fields, data types, scaling/conversion factors, or sensor mappings?

Having access to the original specification would allow me to cross-check the fields I’ve identified and make sure the decoder produces accurate results. My goal is to eventually have a reliable decoder that can also be useful to other members of the satellite/SDR community.

If the documentation is available publicly, I’d really appreciate it if you could point me in the right direction.

Thanks for your help.

Best regards,
Sunil

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Update on this - I’ve since fully reverse-engineered the FUNcube Whole-Orbit telemetry format (with the official FUNcube Nayif-1 Dashboard as reference, decompiled, and validated against 70,368 real records from SatNOGS-archived frames). Since JY1Sat carries the same FUNcube payload and uses the same protocol (ext-id byte 0x10 vs Nayif-1’s 0x08), the same 25-byte WO record format should apply to JY1Sat:

One thing that stands out for JY1Sat specifically: its SSDV frames at ft 32/33 are still reported as “unknown frame type” by gr-satellites, so the 6-bit frame-type enum for JY1Sat is incomplete. If anyone here (@bali) has JY1Sat telemetry documentation or WO/SSDV archives, I’d love to confirm the 25-byte layout carries over and define those frames properly.

Thank you!
73!

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