Quote:
Originally Posted by pmrid
Thanks Slawomir. Interesting article. At airline heights, the chance of a hit over a 15 hour flight can reach 10% or so. But I get these things in every sub and in periods of minutes, not hours. And, other cameras operating at the same site and at the same time are not being affected.
I just can't accept the ray explanation, whatver the suggested source may be.
Peter
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Hi Peter,
The 10% in the paper refers to a chance of a permanent change to a CCD due to cosmic radiation. Typically a CCD will get many more hits by fast moving particles during that time, originating both from the environment and space, resulting in bright pixels and temporary streaks on a CCD that disappear with the next sub.
A particle that hits a CCD face on (perpendicular to the surface of the CCD) will most likely result in one (or few) bright pixel(s) in a sub, while a particle that hits the CCD from a side (parallel to the surface of the CCD) will result in a streak.
CCD gets hit from all directions throughout an exposure, and although most particles hit the CCD approximately face on, a chance of being hit by particles moving across (not through) the CCD increases with time, thus longer subs should have a greater number of longer streaks.
Anyway, that's how I understand this phenomena
