At 01:15 PM 8/26/2012, James Bowery wrote:
Speaking as someone who ran the software development for automated
inspection of ordnance at SAIC:
You always want to characterize your sensors to the greatest degree
that resources permit. In this case, where you've just spent
billions to get the sensor into service, and you are dealing with
scientific data, characterization of marginal pixels is a minor
expense compared to the benefit.
Sure. However, you have just sent your sensors a very long way, for a
long time, in a very hostile environment. A stray cosmic ray can kill
a pixel, or damage it. I'd expect high-resolution image sensors to be
quite vulnerable to this. Most of the electronics can be designed to
be radiation-hardened, but with image arrays, there would be a
trade-off between redundancy (larger pixels, harder to damage) and
resolution (smaller pixels, more sensitive to damage).
And the goals of the mission did not require every pixel be
functional. So I'd think they'd opt for smaller pixels, and tolerate
some occasional damage. I'm glad that the images have the resolution they do!
You seem to be assuming, James, that they might have sent defective
sensors up. I rather doubt that, for exactly the reasons you say.
