kosmos
Differences
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| kosmos [2026/01/30 05:13] – external edit 127.0.0.1 | kosmos [2026/05/06 22:52] (current) – holtz | ||
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| ==== Features / issues ==== | ==== Features / issues ==== | ||
| - | * There is significant pattern noise on the detector that varies from frame to frame, likely providing a larger noise floor than expected from the readout noise alone | + | * There is significant pattern noise on the detector that varies from frame to frame, likely providing a larger noise floor than expected from the readout noise alone. Because of this, users may not want to subtract bias frames: if the noise pattern is different, this will just add noise! |
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| + | * High light levels on the chip, e.g., from calibration lamps, lead to some bleeding of charge into the overscan regions. Users are advised to ignore the first several columns in each overscan strip when determining overscan level. | ||
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| + | * The overscan level varies non-negligibly with row number. | ||
| * There is a Littrow ghost that can appear. Note that this can be seen in flat fields, leading to issues in flat-fielded images if it is not removed from the flat! | * There is a Littrow ghost that can appear. Note that this can be seen in flat fields, leading to issues in flat-fielded images if it is not removed from the flat! | ||
kosmos.txt · Last modified: by holtz