Observation 9417353: MOVE-II (43780)

Hello @DG9MA ,

Regarding Observation 9417353 we are currently testing software to combine recordings from multiple stations during a single overpass to decode more of the binary data.

When you select the “BPSK” transmitter, we will automatically incorporate your recordings in this additional processing. Unfortunately, this does not work with recordings for the “CW” transmitter, because their audio files don’t provide enough bandwidth.

Still, it is cool to see that 6khz bandwidth still contains enough data to recover timing information Observation 9417351:

Each row shows the correlation strength with respect to the chosen reference station (this time orange/LRG). The peak is at the time offset where the decoded data signals match up the most.


Hello @pyBlob ,

i was not aware that my received data is used for any further processing :slightly_smiling_face: I intended to see / decode a CW beacon signal :wink:
Thanks for sharing that image, indeed interesting and I would like to contribute as well with higher bandwith. I’ve just deleted the already planned observations and scheduled a couple of new ones with “BPSK” transmitter selected.

Nice, thank you for taking the time to adjust the observations.

About the CW beacon, I was definitely interested in seeing what the CW decoder would output, as MOVE-II is currently one of the harder satellites to decode. While it has a relatively strong signal, the satellite is currently spinning very fast. This causes the signal to fade away ~4 times per seconds, which is interpreted as the morse-code “E”. We are currently commanding the satellite to slow down, which will take a while. Once it is slower, it should be possible to automatically decode the morse beacon again.

In addition to the command for slowing down we are now requesting dense attitude control data. This is the long data section that is visible in the recent overpasses. Because of the fast turnrate and big adhoc data format, the satnogs stations can only decode ~50% of the packets sent.

Before we started to request attitude control data, we actually used the recorded audio files on satnogs to infer the current turnrate. Every green dot corresponds to a detected ~1s cw/morse beacon. The red line is the average of those. After a longer pause we started to command the satellite again, which gives rise to longer data sections that allow us to infer the turnrate more accurately. The pink crosses show the average turnrate during an overpass by analyzing data sections that are longer than 10s. The dashed vertical lines show when we could confirm success of the slow down commands and dotted lines are confirmed failure.

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20 posts were split to a new topic: Move-II Decoding

2 posts were split to a new topic: Move-II Mission

As there are two long conversations happened based on the initial post on the observation 9417353, I’ve split them into two different threads to be easier to follow them.

One is the discussion on how to decode Move-II and the other is about Move-II mission updates. Let me know in pm if you think the split should be done differently or if I need move posts from one thread to another.

By the way @pyBlob please keep us updated in the other two threads, this is very interesting topic to follow. :slight_smile: