Observation 4084669: FOX-1E (47311)

Regarding Observation 4084669

Hi all,

I see this observation of Fox-1E marked as good and I see what looks like a candidate signal in the waterfall. When I play the audio back I can’t hear anything. I seem to remember that the audio has a 12kHz IF. Is that just in the downloaded files or also when you play the audio on the website?

Either way, I candidate signal for Fox-1E is very interesting. We have not had any confirmation that the telemetry subsystem is alive. I am not an expert at querying the observations. I tried to search for other Fox-1E observations with a signal but could not find any.

73
Chris
AC2CZ / G0KLA

The audio played on the website is the same as what is downloaded, so the signal will be at a 12 kHz IF.

As there is no automatic demodulation of signals from FOX-1E, observations will not be auto-vetted, and so have to be vetted manually. As a result, there are a lot of un-vetted observations. I also note a big gap in observations between may and july, presumably because the sat was considered to be dead.

I’ve scheduled a few observations on my station and the ITR station (one of the biggest in the network) and we’ll see what we get…

73
Mark VK5QI

Here’s a fairly high elevation observation from the ‘big’ station in Adelaide: SatNOGS Network - Observation 4453728

Interesting sidebands on the BPSK signal!

2 Likes

Thanks Mark. And thanks for the recent observation. The observations from 488-W7KKE were from May and correspond almost exactly with the testing we were doing, which included turning up the modulator gain. So we are going to command the modulator to have higher gain again. I’ll confirm when that has happened. We are just getting a command station lined up.

73
Chris
AC2CZ / G0KLA

There is very weak telemetry in these observations but I think the best is from the observation that Mark pointed out. If anyone can see observations with a stronger signal then let me know.

I can decode some of the data from the most recent observation and it does appear to be Fox-1E. I have to turn off the forward error correction and accept the data with errors. We are analyzing data across several frames to work out what the real values are.

If anyone has any further data or suggestions then that would be welcome.

Many thanks to @W7KKE and @vk5qi for the observations.

73
Chris

1 Like

Hi Chris,

We used the 25 meter Dwingeloo radio telescope as a SatNOGS station to listen to Fox-1E: SatNOGS Network - Observation 4554491

We posted some of the info on twitter, tagging AMSAT and Burns Fisher to raise awareness of the observation. See the thread here: https://twitter.com/cgbassa/status/1425414802126610439?s=20

Replaying the IQ file and feeding it to FoxTelem gave some decodes, but as I am a novice with FoxTelem I’m sure there are more frames to be decoded.

2 Likes

@cgbsat thanks!

This is really helpful. We decoded over 100 frames of data from this observation so far. Previously we only decoded 38 frames since launch, so this will be very useful. 100 frames has allowed us to download the entire set of whole orbit data onboard, for example and to download all the stored data for the onboard experiment.

This will help with our diagnostics of what went wrong but will also allow us to pass on data to the experiment owner. For those interested the main experiment is testing the radiation hardness of memory in space and is run by Vanderbilt University. They only need cumulative data from their experiments which run autonomously. So this will give them a snapshot of the experiment status since launch. Very helpful for them.

Any repeat observations you can do would of course be helpful. I don’t know how manual or difficult it was to set this up. If you could repeat this weekly for example, or even monthly, that would be very very helpful.

Thanks again
Chris
G0KLA / AC2CZ

3 Likes

We did some more work on the passes visible on Tuesday, August 10, from Dwingeloo, The Netherlands. And were able to decode another 180+ frames.

The IQ files can be found here: Index of /public/fox1e

Hopefully this will help diagnosing the problems a bit more. Note that these recordings were made using one polarisation only. And as the Dwingeloo telescope is an AZ-EL instrument, the polarisation direction is fixed wrt to Earth.

Anyway, please keep us posted on any progress.

BR,
Harm
PE2HRM / PI9CAM

2 Likes

@harm.munk Harm,

Many thanks for uploading this data. It is a great help. We will analyze it and pass the data to our University experimenters.

One question. You have uploaded the data as “PI9CAM CAMRAS Dwingeloo Radio Te”. I had previously uploaded some data for the team as “2338-PI9CAM-V” given that was the satnogs ground station name. Some more data was uploaded as “PI9CAM/RAW”. You can of course use as many names as you want to help track what you have uploaded. But if you want them combined into one name/total then I can easily do that for you. Let me know.

73
Chris
G0KLA / AC2CZ

1 Like

Hi Chris,

One more thing I forgot to mention. For some time in every pass, the satellite moves too fast for the telescope to keep up. When that happens, we loose the signal for maybe a minute or more until the satellite’s speed on the sky slows down sufficiently for the telescope to catch up.

As for the name: I’ve asked around, and we decided to settle on simply PI9CAM. (Apparently, we have two SatNOG designations, so we don’t want these in the name.)

Thank you for changing that. I keep you posted on the next date we will do an observation of AO-109.

BR,
Harm

Thanks @harm.munk Harm. Understood on the loss of signal when the spacecraft is moving too fast.

I have updated the name to be just PI9CAM and consolidated all the results under that. Many thanks for any future observations you can do.

73
Chris
G0KLA / AC2CZ

Hi Chris,

We’ve been experimenting with scheduling observations with the telescope in a parked position (pointing towards azimuth 210 deg, elevation 30 deg). For satellite passes that pass close enough to this direction, some telemetry may be received, but for others not. This will explain the Fox-1E observations that don’t have any or have little signal in them.

Regards,
Cees

That might be interesting @cgbsat Cees. I would like to see if we get anything. If the signal captured is only a few seconds then we may not get any decodes. The BPSK signal takes a few seconds to be acquired. The decoder has to lock on to the carrier and track it. But hopefully any capture will be long enough to yield a few frames.

73
Chris
G0KLA / AC2CZ