While tracking ERMIS-3 on 401.312 MHz on 4April26 0944Z over EM12kw, during part of the pass two additional signals were also observed. ERMIS-3 was decoded as 9K6 AX100 as expected.
Just up the band however, two additional signals were observed. Up ~18Kc from IQ center, a burst of 5 frames was seen. This was the only time that these signals on ~ 401.330 MHz were observed during the pass. These decoded as 9K6 AX.25 G3RUH true frames. Dest - ESGS01 and Source ABCDEF, which maps to EMISAR which is predicted to be on 401.334 MHz.
To my surprise, the frames seen ~ 40Kc up from IQ center also decoded as 9K6 AX.25 G3RUH true frames. Same Dest - ESGS01 and Source ABCDEF !
Thus, it appears that Unknown1-T16 may be EMISAR transmitting on a second frequency. Be great if others could confirm or offer a different explanation.
IQ is attached. Not a real zip file. Just remove the .zip at the end.
Thus you can not use it to identify the satellites and probably these two signals come from two different satellites. Usually in these cases we try to find which satellites used endurosat comms and try to verify that the found satellite(s) transmit in this frequency or waiting and hoping that after identification of the unknown object there will be information that will connect the NORAD ID with a satellite. For the former If I find some time I’ll take a look in the next week but any help in this task is more than welcome.
OPTISAT (Planetek) on 400.360 MHz - Received/demodulated
PHOBOS (Aethero) on 400.800 MHz - Confirmed via Internet
T.MicroSat-2 (TRON Future) on 401.025 MHz - Received/demodulated
EMISAR (Romanian Inspace Engineering) on 401.334 MHz - Received/demodulated
Unknown (?) on 401.360 MHz - Received/demodulated
Out of the Box (SpaceLocker) on 402.359 MHz - Received/demodulated
One Cubesat is still missing from the above list. Any idea which could be? Also, ARQUIMEA operator has to be matched.
FEMTO-1 (aka ARQSAT-1) could be the unknown one we observe. Also let’s keep in mind that the 7th satellite may not use UHF frequency, thus we haven’t noticed it.
I’m part of the EMISAR operators team at RISE. I confirm that the 5 beacons that N6RFM posted in the first post were from EMISAR. We were able to decode them successfully, big thanks for posting them!
I also confirm that there’s only one transmitting frequency on EMISAR, and Unknown-1 is another satellite, transmitting much more often than EMISAR. Our beacons are 500s apart (a sequence of 5 parts), but our overall power budget is slightly negative while we are detumbling, and therefore the satellite is turned off quite often, until the battery is (partially) recharged.
We still haven’t properly identified which of the objects is EMISAR, and we’re trying to make reliable contact with it. We assume we are “ahead of the pack“, approx 1-2min ahead of the current TLEs.
Thank you Claudiu for the info.
I received the signal from EMISAR on April 1st at 13:13 UTC but it could only be demodulated with the GASPACS version of UZ7HO’s SoundModem.
No results with HS SoundModem Ver 0.27 in FSK G3RUH 9600bd.
This has been observed with all satellites made by EnduroSat, some packets to be demodulated only with the GASPACS SoundModem.
Hi, and thank you for the info. My colleagues confirm that during that time we were attempting to send TCs to the satellite, and this is the response (“sync“ packets - for the handshake, and probably a partial response too). We don’t have visibility inside this protocol and we can’t decode it, as it’s Endurosat proprietary.
Also, we use WFM instead of NFM to receive and decode our satellite (if that matters).
Regards,
this specifically, is a bad idea. what will happen is the following blocks will see a super weak signal drowned in noise.
also, note that gr-satellites has a endurosat deframer with example useage on GASPACS.yml.
you can also adjust the deviation, usually 2400 for 9k6 transmission on the ones I’ve seen, ax.25 example.
2026-04-22T01:35:48 UTC. My latest reception from EMISAR using both FSK G3RUH and GASPACS SoundModems. I tried to send you the decoded frames but EMISAR - Contact form is no longer available.
Hi! Thank you very much for providing more data about our satellite! We currently only receive data during the passes over Romania, and whatever other SatNOGS GroundStation has passes scheduled. Also, I fixed the contact form, thanks for letting me know!
The satellite seems to be stable, yet the batteries are not reaching a full charge state. Still, we are able to send 1-2 commands per day. We managed to enable to beacon to have a 2 min period, and it’s now extend to 7 segments (packets) per beacon. If the satellite is not transmitting beacons, it’s probably charging.
For your information, here is the data included in the 6 packets you received. I know it’s difficult to make sense of it without a full description, but some of them are self-explanatory.
