Space Station SSTV testing event

[dickie757]

27 October 0815 Eastern time is the start of a test session for slow scan TV from ISS.

145.8MHz PD120 coding

There is an EVA on the 30th, so the test session will pause then.

Verification test - Oct 27-Nov 1

The SSTV system in the Service Module will again attempt to verify a replacement piece of hardware during the period of Oct 27 until Nov ...

ariss-sstv.blogspot.com

Good luck!

Go to upper right corner to adjust for your particular location. Dont make the mistake I made one event and look at the passes for NOT your radio location. I was bummed when I thought there were no passes during the event, but actually, there was, but I did not have MY location set.

This page is set for my general location....change it!!

ISS - Visible Passes

Satellite predictions and other astronomical data customised for your location.

heavens-above.com

 

[dickie757]

HT with Robot36 held to speaker. I was getting an adapter to hook up to discone when the picture started. If antenna was hooked up, it would have been a perfect copy. Grrr.

 

[jland138]

Received this image at 09:45 UTC in Northern California using my Kenwood D710-GA and an attic mounted Radio Shack discone.

 

[dragon48]

Got this one today in Jupiter Florida at 14:46 UTC, using a handheld connected to a digital recorder via a 3.5 mm audio cable. Not certain if the rubber antenna was stock or a replacement. This is the best SSTV image I've gotten, and the only complete one I've ever been able to decode:


This one came in roughly five-minutes later, but, unfortunately, looks like the ISS was out of range before my setup could get the entire broadcast:

 

[dickie757]

How you decode? Congrats! Glad to see awesome results.

 

[dragon48]

I first copied the audio file (*.WAV) from the MicroSD card that was in the digital recorder to my Windows 10 Laptop using a card reader. I then connected an inexpensive USB sound card to my laptop - connected to a powered USB hub. I looped a male-to-male 3.5 mm audio cable to the speaker and microphone ports on the sound card. I set the USB speaker and microphone to be the default input and output devices on my laptop.

I then ran the MMSSTV program which can be obtained here:

MMSSTV - HamSoft

Official English Website distributing and supporting amateur radio programs by JE3HHT

hamsoft.ca

I then opened the audio file on my laptop from Audacity, queued up the broadcast start and hit play. MMSSTV then saved both files in a
"history" subdirectory of it default directory in c:\ham.

I then ran a SSTV denoiser program (can be obtained from the SSTV Tools link here - DX Atlas: Amateur Radio software) which cleaned up
the files a little. From that program's output, I saved copies of the files.

 

[jwt873]

I left things running last night and woke up this morning to a couple of images. I use an IC-9700 with a vertical antenna. The rig is tied directly to my computer using a USB cable. The decoding software is MMSTV.

It seems they're running higher power than they have in the past. With previous events, pretty well all of the images I've managed to copy had the odd noise streak in them. This one was clear, with only a bit of skew on the bottom left corner.

 

[jwt873]

 

[vagrant]

@jwt873 - Where did you read about the higher power? Did it convey how much power they were using for this series of transmissions?

 

[dickie757]

......The decoding software is MMSTV......

I uses that, too on this most recent pass, in addition to Robot36 on Android, just speaker into microphone.

......This one was clear, with only a bit of skew on the bottom left corner.

That is a MMSTV setting. In option, setup mmstv, misc tab, lower left in clock area, I changed mine to 8000.60. I used SSTV Encoder in Android to "send" a calibration image.

I got some noise in the middle of the image. I chock it up to bad cables, yeah, thats it, I need to redo my terminations.

I dont think the power got bumped up, but no clue, really.

 

[dragon48]

I'm also getting images with my AOR AR-3000a, but my rig with the antenna outside the patio isn't good enough. I'm in an apartment building, and a parking garage is across from my horizontal antenna. I do see parts of images, but they are far too incomplete to bother sharing anywhere. Some are just slivers of the start of the image.

The good images I posted was from when in was outside in the clear. I was actually in a parking lot, but not close to any structures.

 

[dickie757]

I've run out of passes until they come back on after EVA. Its a pity, because during the shutdown, I have quite a few long overhead passes.

Good luck for the next few hours until shutdown!

@dragon48 Your efforts venturing out to the open lot really paid off, thanks for sharing.

 

[jwt873]

@jwt873 - Where did you read about the higher power? Did it convey how much power they were using for this series of transmissions?

This is sheer speculation... I have no idea how much power they use.

It's just that I'm getting some great noise free images during the current event. I've monitored several previous ISS SSTV events and I've never manged images as good as I'm getting this time around. (No changes to the gear here either).

And here's one I got a short while ago. A little noise near the bottom, but no skew this time.

 

[dragon48]

FYI - my original email notification stated:

There are 2 windows for testing, separated by an EVA:

Fri Oct 27 at 12:15 GMT - Sun Oct 29 at 18:50 GMT
Tue Oct 31 at 10:05 GMT - Wed Nov 01 at 18:10 GMT

However, they never stopped transmitting. I received a partial image today at 14:27 P.M. UTC. Too awful to post, but it's clearly from the ISS.

 

[jwt873]

I managed to hear them this morning 8:00 AM CDT or 13:00 UTC. So they're sill active.

I never planned to be there for the pass., I just sat down in front of the computer to check the forums. The radio volume was off, but I saw an image drawing on the screen. Looked at the radio and the signal it was +10dB over S9.

On the power comment I made in a previous post -- I noticed that it says in the description.. "The purpose of this event is to verify a piece of replacement hardware". Not sure what they replaced, but as I mentioned above.. I'm seeing a reception improvement at my location.

 

[vagrant]

A pass earlier today was odd. I can typically catch it just as I enter the footprint and hold it well for typically two images when a pass is almost directly overhead. My guess is that it was turned off as I did not catch it until five minutes later directly overhead and even then it was wonky. I use a handheld log periodic because of the gain, but I could have just used my discone.

Okay, I'm reading the post by dragon48 and see the comment about "...five minutes later..." In the past the ISS would send for two minutes, off two minutes, send for two minutes and that's what confused me.

As to what I do to decode the image:
1. Audacity - Open original WAV file from the MicroSD card and resample wav to 11025 Hz. (Bottom left corner respample rate)
2. Using Audacity I export the wav file and give it a different name.
3. Rename that newly respampled .wav to .mmv
4. Use MMSSTV to open the .mmv file with the setting to Auto for the decode.
5. Once the image appears I then copy the image from MMSSTV and paste it into something like MS Paint and save out as jpg or whatever.

 

[dragon48]

A pass earlier today was odd. I can typically catch it just as I enter the footprint and hold it well for typically two images when a pass is almost directly overhead. My guess is that it was turned off as I did not catch it until five minutes later directly overhead and even then it was wonky. I use a handheld log periodic because of the gain, but I could have just used my discone.

Okay, I'm reading the post by dragon48 and see the comment about "...five minutes later..." In the past the ISS would send for two minutes, off two minutes, send for two minutes and that's what confused me.

As to what I do to decode the image:
1. Audacity - Open original WAV file from the MicroSD card and resample wav to 11025 Hz. (Bottom left corner respample rate)
2. Using Audacity I export the wav file and give it a different name.
3. Rename that newly respampled .wav to .mmv
4. Use MMSSTV to open the .mmv file with the setting to Auto for the decode.
5. Once the image appears I then copy the image from MMSSTV and paste it into something like MS Paint and save out as jpg or whatever.

View attachment 150558

Nice image. I still have the original audio from these passes. I'll try resampling to 11025 Hz to see whether the images are better.
I got another partial image from my bad patio antenna setup at 05:48 UTC this morning. I should be able to get outside for a very good pass in around three hours. Hopefully, I'll have something worth sharing.

 

[dragon48]

As to what I do to decode the image:
1. Audacity - Open original WAV file from the MicroSD card and resample wav to 11025 Hz. (Bottom left corner respample rate)

Appreciate the advice. The resampling took out some of the grainy parts of my last image. I was hoping for an image I hadn't already received, but that didn't happen. Good news was that at 13:59 UTC, the ISS almost hit me in the head - got to within 30 miles from my 20 at a max 85° angle.

The first image was at the recording's default 44000 Hz. You can see the difference after the resample to 11025. Not a perfect image, (easy to spot a few seconds of lost signals at the start and end) but considering my stock antenna and $7.99 USB sound card, I'm happy:

Edit - probably helped a little, but before decoding the second image, I lowered the amplification, as the first image was overloading MMSSTV the entire time - I always record at full volume on my radio and the highest level for the recorder, as I can always lower the output. I played around with the output amplification until MMSSTV's green indication was around 50% up, just to the point before it ever overloaded.

 

[dickie757]

I wonder what a discriminator tap would do for "cleanliness?"

 

[dickie757]

To answer my own question, I have found out that it depends on the transmitting station. If the tx station has emphasized highs, than rx station might not decode well without de-emphasis