slac_er · HackerTrans

قبل 6 سنواتdiscuss

It ia a single camera with multiple CCD detectors on a common focal plane behind a shutter. It is not a single CCD on a common focal plane. Should there be such a 3.2GP sensor, the noise would be abysmal, silicon would be huge, pixels tiny, and it wouldn’t be all that interesting for astronomy. Note that each 16MP sensor is physically quite large as well.

slac_er

قبل 6 سنواتdiscuss

one image (sensor) at a time. We have multiple types of image processing we will do, some of which happens immediately and some of which happens several months later.

slac_er

قبل 6 سنواتdiscuss

A flat image was taken for bias subtraction and the debris shows up twice because the projector had moved slightly between images, so the image processing ended up subtracting where it didn’t need to and missing the original artifact.

slac_er

قبل 6 سنواتdiscuss

Those are cosmic rays

slac_er

قبل 6 سنواتdiscuss

None of the debris is on the sensors. There is some small amount of dust on a window, and it shows up twice as much due due to image processing performing bias subtraction.

The sensors are in a cryostat, and the effective size you of what you might thing as “dust” in these pictures would be quite large if they had been on the sensors (several mm)

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