According to Kodak airplane travel destroys your digital camera

Started Jul 2, 2011 | Discussions thread
Aku Ankka
Aku Ankka Contributing Member • Posts: 591
Re: And debunked, yesterday...

Joseph S Wisniewski wrote:

Aku Ankka wrote:

According to the paper terrestial cosmic rays do have some effect on creating dead pixels. A round trip by plane from Belgium to Tokyo (roughly 24h total) equals to about 100 days on sea level. Experiments at storing at high altitudes and deep underground were also performed.

Actually, according to that paper, they don't have an effect.

The author of the paper sent his sensors on two different trips, at different altitudes, and there was essentially identical results, the same degradation, or, to quote the author "effects can not be separated from the experimental results,"

I think I'll have to disagree - weird as I almost always agree with pretty much all you post (and I am grateful for your posts as they've prooved to be not only informative, but also great help to kickstart my own thinking process).

I think what you quote means that the effects of different altitude and latitude can not be separated.

I'll quote from the same place in the document you quoted, but a bit more:

With respect to the
results in Figure 3, a few interesting remarks can be made :

notice the increase in probability to create extra hot spots. On the average, sending imagers back and forth to Tokyo corresponds to an increase in hot spot density that is equivalent to a storage of 100 days at sea level. This is fully in line with research done by IBM and Boeing on soft error creation in memories
hot spots with a large amplitude seem to suffer more from this effect

the repeatability of the experiments is remarkable, the two trips in were several months separated from each other,

flying the devices to Tokyo brings them to an higher altitude (33,000 feet) and to a higher latitude as well, Both effects can not be separated from the experimental results, but their effect on the hot spot creation is obvious.

Image sensors were shipped to Tokyo by boat as well : they left the harbor of Rotterdam fro a trip of 40 days to Tokyo. After arrival in Japan they were immediately returned by boat (40 days extra). After a total trip of 80 days the sensors were analyzed again. The results are shown in Figure 4. When the devices travel by a boat, they stay at sea level. If the terrestrial cosmic rays are the cause of the hot spot generation, then shipping the sensors by boat should incur a less pronounced effect than sending them by airplane. Figure 4 proves this statement.

Also storage at high altitude was studied - shelf of the Jungfraujoch lab in Switzerland at 3450m, as was storage deep underground, at the SCK-lab

in Mol, Belgium, 250m below sea level. The resoluts seemed to confirm the differences.

In other words, he subjected two devices to two entirely different levels of cosmic ray exposure and yet got the same result from both. So, it's pretty obvious that, if the level of degradation is totally independent of the level of cosmic ray exposure, that the cosmic ray exposure was not the cause of the degradation observed. It's obviously something that was constant between the two experiments, his handling of the devices, the scans that they were subjected to by airport security, it's unknown.

No, the level of degretatation was different when stored or transported at different altitudes. Also, as I mentioned above, samples were stored at high altitude and deep underground and the results were also in line with the results from the copies that were shipped.

That's apparently why the paper is not peer reviewed or published. The author

It was published (and AFAIK, peer reviewed) in the IEEE Transactions on Electron Devices.

admits it's something he cooked up in his basement. Not necessarily a "bad thing", I've had research published that started off in my basement, but I'm betting his basement isn't like mine, with 6 lab benches, an anechoic chamber, and as many as 3 technicians working on projects.

I want one of those basements too

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