Observation of DJIBOUTI-1A

Satellites & Observations
1

Hello,

For 48 hours, we have not been able to listen to the signal from the DJIBOUTI-1A satellite. the last signal listened to by the satnogs community was on May 30, 2024 at 10:04:54 p.m.

We had a collision alert from the TAURUS R/B satellite on July 01, 2024 at 07:20:31.

Could you please check if DJIBOUTI-1A is emitting signal?

thank you in advance

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2

I’ve scheduled a couple of observations for the next 48h, let’s see if we can get DJIBOUTI-1A.

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3

Well no fancy setup here but…

It fits with the orbital pass, frequency and the audio recorded from previous Satnogs observations.
21:27 utc over the coast of Norway

http://sndup.net/84gn4

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4

The satellite is active as can be seen in this obs

Decoding the replay:

-> Packet from 2k4 FSK AX.25 downlink
Container: 
    header = Container: 
        addresses = ListContainer: 
            Container: 
                callsign = u'F4KJX' (total 5)
                ssid = Container: 
                    ch = True
                    ssid = 0
                    extension = False
            Container: 
                callsign = u'DJIB1A' (total 6)
                ssid = Container: 
                    ch = True
                    ssid = 0
                    extension = True
        control = 0x03
        pid = 0xF0
    info = b'\x8c\x10\xf5\xc0\x85f\xde\xc0\x85f;\x00\x04U\x80i\x03\x00!\x00\x91PU\xc6\xf9\xb5\xc6\xc56`\xea\x0f\x08:\x16q\x166\xf3\xeb\xee\xed\xf2\xcdd\xcd\xb1}\xa7B\x00\x00\x00\xcc\x11f\x01w\x00\x00\xc0\x07na\x00x\x15\x00\x00\x1e\x02\x1f\xd8\x1f\xd8!\x04\xc7\x06\x05\x01\xca\x00\x02\x02\x02\x07\x02d\x00P\x01 \xe1Q\xff\xd4\x00\x18\x00\t\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00DJIBOUTI-1A vous salue !' (total 142)

Hex only:

***** VERBOSE PDU DEBUG PRINT ******
((transmitter . 2k4 FSK AX.25 downlink))
pdu length =        158 bytes
pdu vector contents = 
0000: 8c 68 96 94 b0 40 e0 88 94 92 84 62 82 e1 03 f0 
0010: 8c 10 f5 c0 85 66 de c0 85 66 3b 00 04 55 80 69 
0020: 03 00 21 00 91 50 55 c6 f9 b5 c6 c5 36 60 ea 0f 
0030: 08 3a 16 71 16 36 f3 eb ee ed f2 cd 64 cd b1 7d 
0040: a7 42 00 00 00 cc 11 66 01 77 00 00 c0 07 6e 61 
0050: 00 78 15 00 00 1e 02 1f d8 1f d8 21 04 c7 06 05 
0060: 01 ca 00 02 02 02 07 02 64 00 50 01 20 e1 51 ff 
0070: d4 00 18 00 09 00 00 00 00 00 00 00 00 00 00 00 
0080: 00 00 00 00 00 00 44 4a 49 42 4f 55 54 49 2d 31 
0090: 41 20 76 6f 75 73 20 73 61 6c 75 65 20 21
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5

Hmm, does it have more than 2k4 downlink ? 9790299
compared to 9790300 looks like at least 9k6 ?!
I can take a look at the IQ dumps later today.

6

Confirmed:

-> Packet from 9k6 FSK AX25
Container:
    header = Container:
        addresses = ListContainer:
            Container:
                callsign = u'F4KJX' (total 5)
                ssid = Container:
                    ch = True
                    ssid = 0
                    extension = False
            Container:
                callsign = u'DJIB1A' (total 6)
                ssid = Container:
                    ch = True
                    ssid = 0
                    extension = True
        control = 0x03
        pid = 0xF0
    info = b'\x8c\x10v\x0f\x87fa\x0f\x87f\x10\x00\x04U\xe8\xb7\x04\x00!\x00\x99PU\xcc\xfa\xca\xcc\xccB`\xf0\x0f\x08:\x16{\x16A\xf5\xfb\x02\xf1\xf9\xcdd\xcd\xb4\x80\xafF\x00\x00\x00\xcc\x11h\x01w\x03\x00D\x07xl\x00x\x12~C\x1e\x02\x1f\xc2\x1f\xc2\x13\x04\xc7\x06\x16\x01A\x00\x02\x02\x02\x07\x02x\x00\x18\x01L\xdfL\xff\xcf\x00\x16\x00\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00DJIBOUTI-1A vous salue !' (total 142)
7

Deviation measured to 600 on 2400 baud and 2400 on 9600 baud.

in SatYAML format: DJIBOUTI-1A.yml

name: DJIBOUTI-1A
norad: 58266
data:
  &tlm Telemetry:
    telemetry: ax25
transmitters:
  2k4 FSK AX25:
    frequency: 401.800e+6
    modulation: FSK
    baudrate: 2400
    deviation: 600
    framing: AX.25
    data:
    - *tlm
  9k6 FSK AX25:
    frequency: 401.800e+6
    modulation: FSK
    baudrate: 9600
    deviation: 2400
    framing: AX.25
    data:
    - *tlm
8

Thanks guys for your help,

our satellite avoided the collision and is still operational.

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