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3.1 Discarding read-outs and destructive read-outs

synopsis:  (1) statistical uncertainty increase due to decrease of effective integration time, (2) systematic uncertainty decrease by removing anomalous read-outs.

limitations and applicability:
none

description:
Removal of read-outs along an integration ramp that cannot be used for the derivation of signal (sect.3.5).

purpose correction:
Removal of read-outs that are known to show strong non-linear behaviour during the integration period. This correction prepares the data points (read-outs) for proper processing in the subsequent calibration steps.

uncertainty/noise introduced:
In the worst case the effective integration time is reduced by at most 50%. This happens in case of 4 read-outs per ramp where the first read-out and the destructive read-out are removed; consequently the predicted S/N is reduced by $\sqrt{2}$.

auxillary data:
Cal G file: PSELNDR

keyword(s):
USEDRS : Use destructive readouts? SPD header
DISCNDRS: number of discarded non-destructive read-outs SPD header


next up previous contents
Next: 3.2 Discarding saturated read-outs Up: 3. Derive SPD level Previous: 3. Derive SPD level
ISOPHOT Error Budgets: Derive_SPD Processing Steps, Version 1.0, SAI/98-091/Dc