The ARICA-2 team will run its amateur mission ‘message box’ from September 29th through October 13th.
The satellite has 20 message slots, each capable of storing a message of up to 8 characters for 48 hours.
You may use JI1IZR’s software to create the commands for receiving and transmitting messages.
Make sure to set your modem to 4800 baud with G3RUH scrambling.
This is how the communications went. You can see the logs from the trial operation in Japan.
岩本さん、
Please correct me if I’m wrong.
With Upload you overwrite (if already in use) the selected slot.
With Download you can only downlink the selected slot, there is no ‘give me all slots’.
Do you know
よろしく
ダニエル
Hi Daniel!
You’re correct!
Commands and responses are defined as follows.
On that day, a command from another station went through.
The command is probably Download → Download → Parrot → Download.
Also known as a digipeater, should anyone wish to have a message repeated without using a mailbox slot!
For those interested, here is a implemenation in Linux. Special thanks to JI1IZR, Mr. Sanada, for sharing the Windows version.
Good hunting all,
Bob
N6RFM
Thank you very much for your detailed reply, 岩本さん。
So, Confirm means 'send me an overview of the currently used slots along with the callsigns but not the messages itself’?
If so, it’s presumable to check for a free slot.
@N6RFM’s version greys the field Message ID out for this command. @JI1IZR’s version does it not, but generates the same hex string.
It’s only the online uplink command generator who generates different strings for different Message IDs.
The same is the case for the command Parrot - obviously a digipeater function as @K4KDR describes it - and for the command Upload.
Is this really also correct for Upload 
If so, then
“your message is renewed ‘[message]’ at [slot ID]”
won’t work here. There would be no way to overwrite a slot.
Daniel,
From this vantage point and looking at the disassembled original app: Conclusion - Upload, Confirm, and Parrot all use fixed command bytes with no slot ID encoded anywhere in the frame — only Download computes a byte pair from the Message ID. So there’s no way to target a specific slot on Upload; the satellite must assign it, and any “message renewed at [slot ID]” response is presumably how it reports that assignment back to you, not something you can request in advance.
73,
Bob
I’ve added ARICA-2 to the Digipeater Dashboard.
Thanks Bob! That totally matches the Japanese manual - it says “ARICA-2 automatically assigns 1 slot per callsign”, so no need to select a slot manually.
And here are another examples of these responses:
JI1IZR_01|JA0FKM_02|your message is renewed. 'CQdxFMjp'at 2By Japanese manual, do you mean ARICA-2_Message_使い方.pdf from drive.google.com?
Couldn’t find a text that says 「自動的に」 or something like that for “automatically”.
Anyway, it totally makes sense.
The source was actually the official website: アップリンク フォーマット>展開する> メッセージのアップロード. Saying “automatically” was a bit of a stretch.
Only saw CW over the Eastern U.S. tonight, but seems the 4k8 downlink was active earlier over Japan:
https://x.com/Ja3Tdw/status/2102290134351880247
… I’ve not tracked this satellite previously - is this the normal behavior?
Thanks!
Usually, GMSK beacons are for university missions, not amateur radio!
Today, a trial operation was carried out for a new amateur mission.
Announcement from ARICA-2 Team on AMSAT BB about the conduct of the message exchange mission.
Hello all, just a reminder to update your satyaml’s with the new norad ID (68796) - the old one is still in gr_satellites.
What’s the strategy here with decoding both CW and the 4800 GMSK? I guess I’ll take advantage of SatNOGS’ CW decoder in conjunction with gr_satellites GMSK. Not really sure how to try out the satnogs flowgraphs on test recordings like how you can just call gr_satellites from the terminal. I want to work out the optimal deviation etc so I can submit a pull request to update the satyaml.
Dashboard is great by the way!
Cheers!
For uploads to SatNOGS DB you still have to use 98329.
If you want to feed ARICA-2’s (CW) Dashboard, you would have to manually (decode and) upload the CW data.
For doing this, it’s (for strong signals) sufficient to look at the GMSK record’s spectrogram using an audio editor.
You could also use the records from the SatNOGS’s CW observations, but then you would miss the GMSK stuff.
Daniel
thank you for reminder.
