Wide Field Camera 3
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Definition of Characteristics

Arcsec

Format pixels [Pixels Along Length x Pixels Along Width] The detectors are comprised of a square array of pixels. Each pixel converts light into electrical charge that can be converted into data.
Resolution arcsec/pixel The angular measurement of the patch of sky that one pixel covers. SEE SAMPLE DIAGRAM ABOVE.
Field Size arcsec The angular measurement of the patch of sky that the entire detector covers. Field Size = Fomat x Resolution.
Spectral Range nm The wavelength range a detector is sensitive to. A nanometer is 1 billionth of a meter.
Dark Current e-/pix/sec The pixels of a detector convert light photons into charge. But a detector also accumulates a certain number of electrons per second even when not exposed to light. Better detectors will have lower dark current.
Readout Noise e- The noise in the readout amplifier chain, calibrated into electrons. More noise will make data less precise.
Filters/Grism --- Filters and grisms are optical devices that determine what wavelength of light is exposed to the detector. A single filter or grism is placed in the way of incoming light before it reaches the detector.