Author Topic: Particle Strike Collection  (Read 64777 times)

jules

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Re: Particle Strike Collection
« Reply #15 on: January 18, 2010, 11:09:42 pm »
Not convinced this is a particle strike though I recorded it as such at the time.

I now think it might be an optical effect from out of shot planets. It's the vertical lines coming from the top almost half way across. They just flash for a single frame.
« Last Edit: March 16, 2010, 10:39:49 am by jules »

ElisabethB

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Re: Particle Strike Collection
« Reply #16 on: January 18, 2010, 11:13:15 pm »
It could still be a particle strike. They can come from any direction right !
It's the single frame thing that gives it away for me. I could be wrong though. (moi !  ;D)

lpspieler

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Re: Particle Strike Collection
« Reply #17 on: January 18, 2010, 11:21:43 pm »
Not convinced this is a particle strike though I recorded it as such at the time.

I now think it might be an optical effect from out of shot planets. It's the vertical lines coming from the top almost half way across. They just flash for a single frame.


I have been marking the vertical lines coming out of bright objects as optical effects. It's true that they are especially bright for only a few frames (at least I have seen some of them flash for more than one frame) but most of the time they persist as faint vertical lines as long as a bright object is visible. Also, the position of these persisting lines seems to be locked to bright objects.

jules

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Re: Particle Strike Collection
« Reply #18 on: January 18, 2010, 11:32:29 pm »
Not convinced this is a particle strike though I recorded it as such at the time.

I now think it might be an optical effect from out of shot planets. It's the vertical lines coming from the top almost half way across. They just flash for a single frame.


I have been marking the vertical lines coming out of bright objects as optical effects. It's true that they are especially bright for only a few frames (at least I have seen some of them flash for more than one frame) but most of the time they persist as faint vertical lines as long as a bright object is visible. Also, the position of these persisting lines seems to be locked to bright objects.
Yes - this was my afterthought. The fact that the bright objects were out of frame threw me a little. Next time I'll record them as an optical effect - unless advised otherwise!

Quialiss

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Re: Particle Strike Collection
« Reply #19 on: January 19, 2010, 03:50:23 am »
I was looking for a few more examples of these very faint particle strikes, and while I was doing that I found a very odd one. It looks more like one of our fuzzy faint singular particle strike than anything else, but it's 3 times as thick!



« Last Edit: March 16, 2010, 10:41:15 am by jules »

ChrisScott

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Re: Particle Strike Collection
« Reply #20 on: January 19, 2010, 11:10:46 am »
Not convinced this is a particle strike though I recorded it as such at the time.

I now think it might be an optical effect from out of shot planets. It's the vertical lines coming from the top almost half way across. They just flash for a single frame.

Anything vertical (especially if it leads to a bright star/planet) is almost certainly an effect of the detector being saturated. We can't read too much into the fact that it appeared for a single frame. We are trying our best to supress these from the movies as they are distracting but this is tricky to do sometimes.

The CCD in the camera (the array of pixels) is like a waffle with walls betweel pixels. The light is converted to electrons that fill up these pixels like syrup being poured into the waffle (does it show that the cameras were tested in Belgium?!). The walls to the top and bottom of each pixel are designed to preferentially allow excess signal to 'bleed' into the pixels above and below rather than in some random direction and we have chosen to orientate them vertically in our cameras because the things we are looking for (the solar storms) travel horizontally across the images.

We don't really need to identify these features as we can easily predict and account for them and they don't interfere with our science very often. The optical effects we are more intertested in are those subtle rings and ghost arcs that could otherwise be mistaken for solar features.

ElisabethB is right to point out though that particle strikes can occur from any direction, so some may disguise themselves as CCD bleeding. My guess is that they would be blurrier though (if that's a scientific word!).

Chris.

jules

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Re: Particle Strike Collection
« Reply #21 on: January 19, 2010, 09:14:31 pm »
Thanks for the clarification Chris. So we can ignore the flaring planets and bleeding waffles and concentrate on looking out for arcs, doughnuts and other oddities? Do you want the black blocks / missing pixels recorded too?
« Last Edit: January 19, 2010, 09:19:06 pm by jules »

ElisabethB

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Re: Particle Strike Collection
« Reply #22 on: January 20, 2010, 08:09:50 pm »
here' something I'm not sure about.
It looks like a particle strike, only visible in one screen, but it is much wider.
It's from top right to 3/4 of the screen diagonally.
It is visible in the screen on the right, the one on the left is the screen just before.
In the movie it is much more visible, but I don't know how to attach a video.

« Last Edit: March 16, 2010, 10:43:55 am by jules »

jules

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Re: Particle Strike Collection
« Reply #23 on: January 20, 2010, 08:38:11 pm »
I don't see it (not on my laptop screen anyway).
Just copy and paste the http address of the video Els - it seems to work!

ElisabethB

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Re: Particle Strike Collection
« Reply #24 on: January 20, 2010, 08:42:45 pm »
drats, I didn't save it   >:(

jules

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Re: Particle Strike Collection
« Reply #25 on: January 20, 2010, 10:10:39 pm »
drats, I didn't save it   >:(
I've done that! ::)

Quialiss

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Re: Particle Strike Collection
« Reply #26 on: January 21, 2010, 01:30:21 am »
here' something I'm not sure about.
It looks like a particle strike, only visible in one screen, but it is much wider.
It's from top right to 3/4 of the screen diagonally.
It is visible in the screen on the right, the one on the left is the screen just before.
In the movie it is much more visible, but I don't know how to attach a video.

I think I see it, very fuzzy, it looks almost like part of the solar wind, except it wasn't there a second ago.  I posted something like this a few posts up, it's a bit brighter.  It's about 3/4 of the way through this video, and it appears to have a more 'typical' companion in the bottom right of the same frame. http://solarstormwatch.com/favourites/82
« Last Edit: March 16, 2010, 10:45:08 am by jules »

ChrisScott

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Re: Particle Strike Collection
« Reply #27 on: January 21, 2010, 01:34:13 pm »
here' something I'm not sure about.
It looks like a particle strike, only visible in one screen, but it is much wider.
It's from top right to 3/4 of the screen diagonally.
It is visible in the screen on the right, the one on the left is the screen just before.
In the movie it is much more visible, but I don't know how to attach a video.

I think I see it, very fuzzy, it looks almost like part of the solar wind, except it wasn't there a second ago.  I posted something like this a few posts up, it's a bit brighter.  It's about 3/4 of the way through this video, and it appears to have a more 'typical' companion in the bottom right of the same frame. http://solarstormwatch.com/favourites/82

Intriguing. I'd put it down as a particle strike as it has all the characteristics save for being quite wide which, presumably, means it was close to the camera. I'll bring it up at the next team meeting to see if anyone has an alternate theory.

Thanks again, great stuff as usual!

Chris.

ElisabethB

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Re: Particle Strike Collection
« Reply #28 on: January 21, 2010, 07:09:31 pm »
Hi Chris tx for all the explanations
What do we do about this one(the white line, only visible in one frame)? Is it a bleeding signal ?
Do we ignore it or is it 'something else' ?
« Last Edit: March 16, 2010, 10:45:46 am by jules »

ElisabethB

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Re: Particle Strike Collection
« Reply #29 on: January 21, 2010, 08:16:33 pm »
Quote
Intriguing. I'd put it down as a particle strike as it has all the characteristics save for being quite wide which, presumably, means it was close to the camera. I'll bring it up at the next team meeting to see if anyone has an alternate theory. 

here is a more visible example

« Last Edit: March 16, 2010, 10:46:13 am by jules »