CALPRODUCT-NI-012: NISP Persistence¶
Parent requirement¶
Scheduling¶
Twice, during PV phase.
Monthly, if NISP inoculation is done.
Time-critical¶
Must be taken 1-2 weeks after CALBLOCK-PV-010: NISP LED flats, to rule out any long-term effects from the flat fields.
Dependencies¶
CALBLOCK-PV-010: NISP LED flats must be done at least 1-2 weeks before, as it could affect the persistence.
Objective¶
Persistence has been characterized extensively on ground, when the detectors were turned on while still being warm. A subsequent calibration campaign with detectors turned on when cold followed. The idea is that the timescales of the traps do not change, just their overall amount per pixel. Using the second calibration campaign one can then update the relevant parameters in the models.
In flight, detectors are turned on cold, when persistence is significantly lower.
The objective of this calibration product is to measure the time constants and persistence amplitudes at a time when persistence from prior illumination events can be neglected, and update the models accordingly.
Persistence in Euclid H2RGs has been shown to be achromatic (A. Wacynski, NISP DWG5 2015), hence we test only with a single LED.
Fulfilled by¶
In-orbit duration¶
Data volume¶
58176 MB
27*NP for photo-MAC flats, 150*NP for the photo-MACC darks, and 300*NS for the spectro-MACC darks.
Processing input¶
Ground Processing Input Data: Darks (without persistence)
Data Description: 27 flat fields, 150 photo-MACC darks, 300 spectro-MACC darks (overall for the nominal and the check sequences)
Required accuracy, constraints¶
Must be able to evaluate the persistence signal per pixel.
Validation¶
Compare the observed persistence (flats, bright stars) with the predictions by the persistence model. Update the time constants and amplitudes if statististically significantly different from ground test data.
Recovery¶
A significant change in observed persistence behaviour requires an update of the persistence model. The persistence model is used to compute the persistence map, which in turn is used to determine the most likely contribution of persistence to a source flux measurement.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
NISP-P calibration scientist