How It Sees

Goodbye to all that
This is the final cleaned-up image. How did we banish the blizzard? First, we flagged sharp features appearing in one image but not the other as cosmic-ray garbage and discarded them. Then we combined the two "snow"-free images to improve the signal-to-noise ratio. We also corrected for a number of instrumental effects with names like "dark current," "flat fields," and "charge transfer inefficiencies." No need to bore you with details of those effects, even though as a member of the team that built the camera I spent a couple of years figuring out how to characterize and remove them!

Despite all these efforts, some cosmic rays and other defects remain that we need to jettison.

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