Soyuz-2-1b Fregat-M (METEOR M N2-2) launch on 2019-07-05


Station #40, operating in STRF mode in the UHF, received signals from the following objects at the listed frequencies. The object names follow the frequency list by Vlad Chorney (V2b: This is from a single pass, so the IDs may change in the future.

44403 435.950  BeeSat 9-13
44394 436.250  AmGU-1
      436.000  Socrat
44393 435.700  JAISAT-1, EXO CONNECT, LightSat (multiple signals)
44392 436.500  VDNH-80
44406 437.525  LUCKY-7


99809 - SONATE goes better with 44419 than with 44398 according to satnogs


Thanks I’ve changed it…


Hi from the SONATE Team,

we would be interested in how you come to that conclusion?
On what information do you base that?


Hi everyone,

we plan to communicate with SONATE in UHF
tomorrow (08.07) at the pass over
Europe at roughly 13:10 UTC.
And also for the following pass at roughly 14:45 UTC.
Can you schedule some observations for these passes?

Thanks in advance!


I’m going to schedule observations for this launch later today, so I’ll have it in mind, thanks for letting us know.

@laid @clex @orangetom
I can not find a public source for the encoding schema you use for your frames that your satellites transmit on the amateur frequencies. Can you please point me on them or publish them here.

Thank you!


I see that SONATE also has S-band antennas:

At which S-band frequency does it transmit, and what modulation is it? This may allow us to quickly identify the NORAD ID belonging to SONATE.


In the 4S Symposium 2018 Proceedings is the S-band frequency between 2261MHz-2271MHz described. Try 2261, 2263, 2265,…2271



Based on latest NORAD data, we assume the TTU101 be on the cluster with ID 44398

1 44398U 19038N   19188.21985067  .00004875  00000-0  28917-3 0  9998
2 44398  97.4858 150.1516 0024688 238.1626 121.7205 15.11562409   266

TTU101 has UHF radio at 435.45 MHz, and should be transmitting 9600 bps, 2FSK modulated, GR3UH encoded AX.25 telemetry frames every 3 minutes or so, addressed to ground station callsign.

Please note, that it is currently a 100ms burst after every 3 minutes, so waterfalls are pretty mute even if good data is received…

TTU101 callsign is ES1ZWS, ground station callsign is ES1ZW

The overall frame structure for TTU101 is

16 bytes   AX.25 header
4 bytes    command header
variable   command payload to end of frame, up to 251 bytes

Command header structure is

4 bits     sending module, 0=groundstation
4 bits     intended receiver module, 0=groundstation
8 bits     command sequence #
16 bits    command, little endian number. 4 highest bits are flags
           bit15 - response bit (the packet is response to command)
           bit14 - error bit    (the command produced error)

current TTU101 telemetry command number is 0x555 and payload structure is

typedef struct
        u_obc_m,    // main OBC power rail volage, mV
        u_obc_b,    // backup OBC power rail voltage, mV
        u_comx,     // xband transmitter power rail voltage, mV
        u_com,      // UHF radio power rail voltage, mV
        u_adcs,     // ADCS power rail voltage, mV
        u_beacon,   // backup radio power rail voltage, mV
        u_sol,      // solar cell power rail (input to EPS) voltage, mV
        u_bata,     // battery A voltage, mV
        i_obc,      // main OBC consumed current, mA
        u_radsens1, // radiation sensor 1 measured voltage, mV
        u_radsens2, // radiation sensor 2 measured voltage, mV
        u_radref,   // radiation sensor reference measured voltage, mV
        com_resets; // COM module power-cycled counter due to unresponsiveness
        eps_status, // latest received EPS status (in response to keepalive)
        eps_checks, // number of commands sent to EPS from last reset or response
        com_checks, // number of pings sent to COM from last reset or response
        obcm_checks,// number of pings sent to main OBC since last response
        obcb_checks;// number of pings sent to backup OBC since last response
} telemetry_t;

Example of complete telemetry frame:

8a a6 62 b4 ae 40 60 8a a6 62 b4 ae a6 61 03 f0 
a0 86 55 05 6e 13 74 13 00 00 53 13 00 00 fc 03 
34 0c 00 00 00 00 54 13 08 0b 16 05 1a 00 02 00 
00 00 00 00 38 01 29 10 2c 01 2f 10 1d 04 

The above is a command sent from module 10 to module 0 (groundstation), with sequence number 0x86 and command number 0x555. It is not a response, as the response bit in the command number field is zero. The telemetry data is

6e 13 - main OBC power rail voltage, 4974 mV
74 13 - backup OBC power rail voltage, 4980 mV
00 00 - Xband transmitter power rail voltage, 0 mV
53 13 - UHF radio power rail voltage, 4947 mV 

Best Regards,



Hi folks,
especially @fredy and @cgbsat.

The telemetry format will be published (as soon as our webmaster works) here:

It’s basically CCSDS source packets/transfer frames packed in AX25 frames.
Times were quite busy - so sorry about the delayed publication.

With the next pass (about 13:10 UTC) over Europe we will try to turn on the telemetry on UHF with a rate of one frame every 2 seconds for 20minutes. Additionally, we’ll try to activate a morse beacon of the callsign (DP0SNT) on our VHF (lasts about 10 seconds) for every 30seconds for the next two hours. We track the NORAD object 44400 (2019-038Q) but are not 100% sure if it’s actually us :stuck_out_tongue:

The idea using the S-band transmitter to identify the sat is quite neat. But we won’t turn it on until we haven’t fully acquired the satellite’s state as it’s consuming quite some power :wink:

Cheers and always good signals


I’ve scheduled some passes on VHF for the next two hours… Just to be sure, you are going to transmit at 145.840 MHz right? If yes just have in mind that in the same frequency is also MOVE-IIb.


In the absence of S-band, then certainly CW (Morse code) on VHF will also be very helpful for comparing the Doppler curve to TLEs. I will try to obtain a Doppler curve on the next pass over Europe.


Thanks @fredy and @cgbsat, you’re awesome =)

We were quite successfull tracking said NORAD object (44400 2019-038Q) and could decode around 50 frames.

Unfortunately we had no time left to activate the VHF beacon.
And yes the VHF frequency is 145.840MHz is correct - and yes it’s the same as MOVE-IIb.



Too bad about the VHF beacon. Can you confirm that there will be no VHF transmissions on the next pass?



what I can confirm for now is that we plan UHF communication.
Pointing at Object-Q ID 44000
Stay tuned for updates


Further news,
we are planning to activate VHF
I will get back to you with the timings and everything once we know wether it was activated or not


Changed it in network so now observation will follow 44400


VHF, unfortunately, is not activated


@laid 435.35 MHz or 435.45 MHz?


The documentation of our main telemetry format is now available. It will be updated for the other APIDs soon.

Furthermore, we plan the next activieties for tomorrow (early in the) morning (July 09, ~2:15UTC) during the passes over Europe.
Besides other activities, we’ll retry to activate the CW VHF beacon. But once again that’s not the main goal of the passes and might be skipped. We’ll confirm the activation here asap.

Thanks again and stay tuned :slight_smile: