CALPRODUCT-VS-027: VIS Persistence¶
Parent requirement¶
Scheduling¶
Early in PV phase
Time-critical¶
No
Objective¶
The VIS detectors do show some latency, from photo-electrons gradually released from charge traps. However, if a 0.5 surface inversion is applied after an exposure, followed by 3 flushes, no latency could be detected anymore in the ground tests. This procedure (surface inversion, flushes) is automatically executed after every VIS exposure.
The purpose of this calibration is to test that the procedure is still effective in flight.
A correction of persistence is not foreseen in the SGS pipeline, in particular if the sources are deeply saturating and their true flux is unknown. If persistence is present, then the corresponding pixels in subsequent exposures could be flagged or masked.
Fulfilled by¶
Data volume¶
VB + 4*VD + VF = 2516 MB
bias (x1), dark (x4), saturating flat (x1)
Processing input¶
Ground Processing Input Data:
Data Description:
Processing method¶
Compare the average signal per quadrant in the darks following the flat exposure, with the corresponding dark signal prior to the illumination.
Required accuracy, constraints¶
TBW
Processing tools¶
TBW
Recovery¶
Repeat.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
VIS instrument scientist