Soyuz 2-1b Fregat-M 2020-09-28

Satellites & Observations Launches
21

Hey @N6RFM,

SatNOGS policy: As you can see here we are trying to gather all needed information from the team in order to determine our approach. Indeed the satellite is not IARU coordinated though, but not declined either. In principle we would like to examine how this is a violation or not of the radio amateur service. What is the intended and actual usage? Are all demodulation and decoding information available?

22

Maybe playing devilā€™s advocate here, but keep in mind that in some countries IARU coordination isnā€™t required by their national administration to register and launch a satellite. Voluntarily submitting a coordination request is always desirable, but in some countries people often donā€™t speak enough English to understand the important role that IARU plays or to submit the required documentation.

So gathering all possible information at this early stage as @pierros said is the wisest choice.

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23

Thanks @pierros and @EA4GPZ for points to consider. Offering to educate/assist always a good way to go first.

24

Regarding NORBI, I received the following info from R4UAB earlier today:

436.700, 1-minute interval, alternating between 9k6 FSK & 250 KHz LoRa.

I did receive very weak but ā€œ9k6-lookingā€ signals around 436.700 on a pass over the Eastern U.S. today.

R4UAB provided the following document w/ additional specs:

ā€¦ which I ran thru Google Translate & re-saved as:

-Scott, K4KDR

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25

DECART new freq: 437.000 MHz MOBITEX 4800bd

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26

@R4UAB For Norby, do you know if a syncword used for the LoRa frames? TKS es 73. Bob

27

Iā€™ve changed it in DB, is there any online source for this or you have communicated with the team?

28

Hi @K4KDR and @R4UAB, thanks for the information about NORBI. For FSK, I guess itā€™s using the built-in packet mode of the LoRa tranceiver SX1268 or similar, including whitening and CRC. However, Iā€™m missing some information I need to implement a decoder.

  • What syncword are you using? (I think a syncword is mandatory)
  • Are you using the fixed-length format or the variable-length format?
  • Are you using an address byte?
  • Which one of the supported CRC types are you using?

Any pointers are helpful. For instance, I could use something like ā€œweā€™re using this chip and these register settingsā€, or ā€œweā€™re using RadioLib and configuring it like soā€.

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29

A quick update:
SALSAT, MEZNSAT and DEKART has been received in several observations.

Nothing from NETSATs or NORBY

30

Regarding DEKART I have used Observation 2910139 to check that the format is exactly the same as D-STAR ONE, AMGU-1 and SOKRAT (DEKART and SOKRAT seem to come from the same line of ā€œphilosopher satellitesā€ hahahaha).

To decode, this needs the Mobitex-NX decoder in beesat-sdr, which Iā€™ve just ported over to GNU Radio 3.8 (see the maint-3.8 branch in my fork). There are a few example flowgraphs in gr-satellites under examples/satellites/nx_decoder to get you started.

Probably Iā€™ll include in gr-satellites the relevant parts of the decoder so that we can have a more streamlined decoder process, especially since beesat-sdr seems a bit unmaintained.

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31

By decoding this signal all NETSATs (with callsigns DP2NSA-D) are heard.

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32

if this is the case than also this signal contains call signs

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33

Hi!, YARILO-1/2 freq 435.350/435.550 MHz BW: 20 kHz.

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34

I have direct contact with the team. This can be considered official information.

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35

Unfortunately, I do not have such information yet.

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36

@R4UAB Thanks you. I did try listening for Norby LoRa with an Sx126x system, using the parameters below (RadioLib 4.1). These are based on the document shared. No decodes. Unsure about the syncword and other paramaters. 73 es GL>

// modem configuration
#define FREQUENCY 436.7 // MHz
#define BANDWIDTH 250.0 // kHz
#define SPREADING_FACTOR 10
#define CODING_RATE 5
#define SYNC_WORD 0xAA // used as LoRa ā€œsync wordā€, or twice repeated as FSK sync word
#define OUTPUT_POWER 20 // dBm
#define CURRENT_LIMIT 140 // mA
#define LORA_PREAMBLE_LEN 8 // symbols
#define BIT_RATE 9.6 // kbps
#define FREQ_DEV 5.0 // kHz SSB
#define RX_BANDWIDTH 39.0 // kHz SSB
#define FSK_PREAMBLE_LEN 8 // bits
#define DATA_SHAPING RADIOLIB_SHAPING_1_0 // BT product
#define TCXO_VOLTAGE 0 // volts
#define WHITENING_INITIAL 0x1FF // initial whitening LFSR value

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37

We have new TLE for SALSAT generate from strf tool by @cgbsat and @pierros:

1 99826U          20273.50000000  .00000000  00000-0 -97931-4 0    00
2 99826  97.6633 206.9860 0016341 242.6979 234.0215 15.03154723    03

Future observations will automatically move to these TLE set in Network.

cc @bastla

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38

Thanks! Satellites are added in DB.

@R4UAB any info about their modulation mode?

39

@bastla does SALSAT transmit only over Europe?

40

@fredy Thanks for your TLE update. We also already have a first guess of our current orbital time offset and will check your data tomorrow. To prevent unintended transmissions due to possible malfunctions the TUBiX10 design decision some years ago was to only transmit if the TNC is triggered. So yes, for a foreseeable time there will be just signals over Europe for now.

P.S.: The core system was checked out last night and today, so the exhausted team is going to take the night off. Operations are going to continue ~1200 UTC.

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