Can someone tell me what the T# parameters mean on this APRS signal from Lapan-A2? Thanks!
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Hi Simon,
One month ago, I asked YD2CLX Havid about that. According to him this data just contains a voltage and a temperature value but he has to look again for the structure so I’m still waiting for his return on this topic.
My decoder parses these beacons already. Once we know what these numbers mean, we can build a dashboard.
However, the most exciting part is on UHF. There is also a beacon (UHF beacons from observations).
It’s also at 1200 bit/s, but MSK (=Minimum Shift Keying) (=FFSK) modulated and with the tones at 1200 and 1800 Hz (compared to 1200 and 2200 Hz of regular Bell 202 standard). Should be similar to Lapan-Tubsat.
Unfortunately, I have had no luck yet on decoding it.
By the way, you’ve seen the IO-86 row on my Digipeater Dashboard?
I noticed that I even built a telemetry dashboard for IO-86.
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Hello, I may have partial information about the Lapan-A2 APRS data. It came after I watched this webinar from AMSAT-ID and read the Argent Data Systems Tracker2 model OT2m manual (here is OT-3m that is similar), the module that is used onboard Lapan A2 for the APRS.
For example one beacon that I received last night:
T#017,140,204,254,000,000,00000010
The first number after T# which is 017 means the sequence number after the APRS module has been turned on, so if we read the schedule shared from PRTeksat, it will always turned on above India, went a full orbit and turned off above Papua/Oceania. So it means I get the 17th packet after it turned on.
Second number is the onboard voltage in tenth of a volt, so 140 means 14.0V. Also APOT21 should be the Argent data systems Tracker2 model OT2m.
Then there is the unknown #3 and #4 data which is the A1 and A2 input to the modem. I’ve read several journal about the satellite but I haven’t find out what it is, all we know its a tenth of a volt. From what I speculate, it may be the onboard temperature or something with the solar panels. First number most of the time range from 196 to 204 and the second number is either low 001 to 002 or high 253 to 254.
I may ask someone from PRTeksat about this and hopefully we can have a complete telemetry data.
Wow, thank you very much for making this dashboard! Looks like now its a full circle, I remember clearly almost exactly a year ago that you reached me in DM to taught me how to upload IO-86’s APRS data to the SatNOGS, probably that is the first time I contribute to SatNOGS 
By the way do you think it is possible to add additional information about the telemetry on that dashboard? I will find more information about the rest of two unknown data.
About this, it should be the satellite TT&C data when it is above its ground station in Rancabungur, its always shown on “work days” 9-5 and @verdantfoster and @bali confirmed that.
Thanks, I hope this is usefull!
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Thank you Adhito for going into that matter.
I’m still waiting for an answer from YD2CLX Havid regarding the telemetry values.
Would be happy to extend the decoder to show every single value.
Let me know your progress.
Daniel
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Hi, Daniel.
Unfortunately I think its going to be a dead end due to the lack of official documentation. I have asked directly to both YD0NXX and YD2CLX but unsuccessfully getting any written report of what is what. Assembly started around 2008 - 2012 and it (the APRS telemetry system) is on the amateur payload side so I may understand that.
But I just found about 17000+ APRS telemetry packets from your dashboard, thanks for that 
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