ISS SSTV: MAI SSTV on Dec. 4, 5 and 6

Satellites & Observations
1

Hi Fredy
cant get the iss sstv to go active via citatrion route , like last time ?

The ISS crew is scheduled to activate the MAI SSTV experiment for short periods of time on Dec 4, 5 and 6. Those times in UTC are below.

Dec 4: On - 12:00 UTC, Off - 16:50 UTC
Dec 5: On - 11:25 UTC, Off - 17:15 UTC
Dec 6: On - 10:20 UTC, Off - 16:40 UTC

Down link will be on 145.800 MHz.

see https://ariss-sstv.blogspot.com/

Max

1 Like
2

Do you get any error?

Thanks for the info I’ll move this to a new thread for better visibility and I’ll take care of the transmitter.

3

@blueskies I’ve just checked, your suggestions were added fine, just have in mind that they are manually reviewed, so it takes sometime until it is reviewed. So now SSTV is again active. I’m going to schedule some observations.

4

thank you Fredy , i tried at work and i don’t think i waited long enough for the page to refresh , i tried again at home i think it did work and added the request to the queue
cheers

Max

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5

SSTV Images :

https://network.satnogs.org/observations/1307007/
https://network.satnogs.org/observations/1306789/
https://network.satnogs.org/observations/1306880/
https://network.satnogs.org/observations/1311009/
https://network.satnogs.org/observations/1310420/
https://network.satnogs.org/observations/1310851/
https://network.satnogs.org/observations/1310852/

6

Thank you @fredy for scheduling passes on my station!
Can you point me to a topic where you explain how you decode them? I assume you are downloading the audio via the network API and uploading the images, because AFAIK my satnogs station doesn’t have a decoder for SSTV.

7

I download audio via https://network.satnogs.org/observations and convert ogg to 16 bit pcm stéréo 48k wav file with audacity. Then I decode using multipsk, convert bmp to png and rename file data-[id_observations]-[date_heure_obersations]_[number_of_image].png. Upload files to satnogs station, give file right to satnogs user and move to /tmp/.satnogs/data.

4 Likes
8

Wow! I thought it was automated :smiley: (and I thought it was Fredy… sorry)
Thank you for your work!

1 Like
9

Morning
If you want to have a try you can just play the audio through your speakers into an app like robot36 on android ( https://play.google.com/store/apps/details?id=xdsopl.robot36&hl=en) or on apple ( https://apps.apple.com/us/app/sstv-slow-scan-tv/id387910013 ) or on your pc try virtual cable and MMSSTV ( https://spacecomms.wordpress.com/decoding-iss-sstv-audio-recordings-with-a-virtual-audio-cable/ ) and https://www.youtube.com/watch?v=WYQavqCbRBQ
but just play the ogg file of the audio / the observation - don’t forget to change the audio settings to the virial cable. Its fun to do on the pasess where you have a good clean image .
enjoy

10

Some stations are testing experimental automatic decoding of SSTV images, via GNU Radio if I remember correctly.

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11

Just to be clear, as @elkos said there are couple of stations that either automatically or manually decode and upload their results in observations.

My implementation is a script that checks for SSTV observations (between specific datetimes) and if there are any vetted as good without any data uploaded then it downloads the audio, convert it to wav and then feed it to a modified qsstv version, if there is any decoded image then uploads it to the observation.

The modified version of qsstv can do:

  1. Start from command line with parameters the name and the audio file for decoding
  2. Start decoding of the audio without any external interaction
  3. Calculates and add to the name of the file the right datetime for the decoded image
  4. Exits after the end of scanning the audio file.

It’s a hackish version that I have promised to upload but I haven’t done it yet :frowning:

Ideally we should soon add in gr-satnogs the decoder of @ar3itrary that gave very good results in the last two SSTV events.

3 Likes
12

@michel do you resize the images that you upload or this is the size that your decoder produce?

13

It’s size produce by multipsk.
MULTIPSK Documentation :

Notes relatives to the PD120, 180 et 240 modes:

These are modes normally displayed on a 640x480(+16) window. Multipsk displays the pictures of these modes on a standard 320x240(+16) window, which implies a picture area 4 times smaller but a better picture quality as all the information are taken. As the Multipsk transmission window is 320x256, these modes are not proposed for transmission. The user would, in a worthwhile way, used the PD90 mode.

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14

Thank you for these instructions! I just used them for this observation:
https://network.satnogs.org/observations/1316855/