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Sun in extreme UV, kind of....


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I don't know if this would be considered as cheating on another level, but here I go:)

Since I also have an interest in weather satellites and radio astronomy I regularly receive weather images from Russian, European, Chinese and American weather satellites. Some time ago I became aware of a European satellite imaging the sun in extreme ultraviolet and dumping the images when in range of Belgium (location of headquarters). This is all done at a frequency of 2235MHz and can be received with moderate equipment.

Here is my first image received from the Proba 2 satellite
Image

The noise is due to the sensor on the satellite itself, so unfortunately there isn't much to do about it.
The setup is fairly simple, a 100X60cm parabolic wifi grid dish, an SPF 5189 low noise amplifier and a Hack RF software defined radio. Everything is mounted on top of my AZ4 mount head which is great for hand tracking the satellites.

Image

Here is an image of the received signal just as the satellite started transmitting the images.
Image

I hope this is accepted in this topic, since I didn't really capture the image myself, although the image is fresh off the memory of the satellite so not more than a couple hours old from the time of reception. Best of all, you don't need clear skies to get these images;)

Victor

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8 minutes ago, CraigT82 said:

Fantastic Victor!  Do you know what the wavelength of the satellite image capute is? 

Ahh sorry Craig, didn't notice the edit:) It captures the sun at 17.4nm so far lower than the usual UV many people think of. Here's a little read about the mission in case you or others fancy giving it a read:
https://www.cosmos.esa.int/web/proba-2/swap

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Wow that really is extreme UV! The SWAP optical design is pretty interesting too.  I wonder how these images are interpreted, the solar surface looks very heterogeneous at this wavelength with the very bright spots and dark zones.

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11 minutes ago, CraigT82 said:

Wow that really is extreme UV! The SWAP optical design is pretty interesting too.  I wonder how these images are interpreted, the solar surface looks very heterogeneous at this wavelength with the very bright spots and dark zones.

Definitely!! It's quite interesting how different the sun looks depending on the wavelength.

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That's genius. I love the idea of gentleperson amateurs just picking up satellite downloads.  👏🏾

Btw, if that's fixed pattern noise, maybe the scientists would be kind enough to share a masterdark with you!

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3 minutes ago, vineyard said:

That's genius. I love the idea of gentleperson amateurs just picking up satellite downloads.  👏🏾

Btw, if that's fixed pattern noise, maybe the scientists would be kind enough to share a masterdark with you!

Thank you:biggrin: I received a total of 16 images in a single pass and the pattern seems to be fixed so it's definitely not a bad idea!! Talk about an astrophotography and radio knowledge collab😅

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4 hours ago, ZiHao said:

Very interesting results Victor! Can't wait to see more reports like these.

Thanks ZiHao:) It seems that people actually like these so will most likely share some more at some point:)

1 hour ago, Altocumulus said:

Intriguing and surprising what one can pick up from the airwaves!

I did wonder what you were doing with that antenna outside at night :D

Indeed! There's so much you don't know about just because you can't see it. It's a whole new world in many ways.

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12 hours ago, Victor Boesen said:

Thank you:biggrin: I received a total of 16 images in a single pass and the pattern seems to be fixed so it's definitely not a bad idea!! Talk about an astrophotography and radio knowledge collab😅

Maybe you can even extract FPN from those 16 images?

As first approximation, I would do following:

- Take each of 16 images and apply 3x3 median filter on them.

- Subtract each median image from corresponding original image

- Average residuals or maybe even do sigma clip stacking on them

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16 minutes ago, Mr Spock said:

That's a fascinating image and such a lot going on. It would be nice to see more of these.

 

3 minutes ago, BCN_Sean said:

That's triggering my inner geek no-end.  The whole process here, not just the image I'm finding so interesting; I'd be keen to see some more of these.

Thank you both of you!! It seems like this won't be the last one I share on here then:) Didn't know what to expect since it isn't me directly capturing the image.

5 minutes ago, vlaiv said:

Maybe you can even extract FPN from those 16 images?

As first approximation, I would do following:

- Take each of 16 images and apply 3x3 median filter on them.

- Subtract each median image from corresponding original image

- Average residuals or maybe even do sigma clip stacking on them

The only problem with this that I can think of is that the sun isn't centered in the exact same spot in all images, and that the roll of the satellite changes in some images. This would make it harder to do FPN I guess? The sun could be centered and rotated with OpenCV, but then the noise wouldn't be fixed.

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4 minutes ago, Victor Boesen said:

The only problem with this that I can think of is that the sun isn't centered in the exact same spot in all images, and that the roll of the satellite changes in some images. This would make it harder to do FPN I guess? The sun could be centered and rotated with OpenCV, but then the noise wouldn't be fixed.

As long as noise is in the same place in each of the images - above extraction will work.

If noise also shifts for some reason but pattern stays the same - you could first align on noise rather than on image detail and then perform above.

Then you would need to align that master to each image again when calibrating.

 

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Just now, vlaiv said:

As long as noise is in the same place in each of the images - above extraction will work.

If noise also shifts for some reason but pattern stays the same - you could first align on noise rather than on image detail and then perform above.

Then you would need to align that master to each image again when calibrating.

 

I briefly talked to the creater of the decoding & demodulating software and he's also aware that this is possible. He'll probably implement it at some point:))

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12 hours ago, PXR-5 said:

Pretty darn cool 😎

Thank you:)) I enjoy it very much!

24 minutes ago, Montana said:

Wow!! that is incredible! how did you know about the broadcast? what else do you download 😉

I'm apart of a community of radio enthusiasts who receive all sorts of satellites in wide variety of frequencies. A couple months ago we started exploring the possibility of receiving Proba 1 & 2(which is the one I received here). Since then software has been developed to demodulate and decode the signal to get images from them. A lot of this hobby is built upon amateurs across the world and reverse engineering signal modulation because of poor documentation.

I also regularly receive weather images and do hydrogen line observing with my own software.

It's really amazing what amateurs can do nowadays and I'm happy to be apart of it!

27 minutes ago, tooth_dr said:

Amazing!  Love that view.  What a set up too.

Thank you:) The AZ4 and a light weight photo tripod is coming in handy😅

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