CALPRODUCT-NI-015: NISP Snowballs¶
Parent requirement¶
Not in the CalCD-B. This is not a calibration activity, but a characterisation of isolated spurious events.
Scheduling¶
Once, during PV phase.
In case of failure, repeat at next possible opportunity.
Time-critical¶
No
Objective¶
Snowballs are highly energetic events that originate probably from cosmics, and / or radioactive decay in the detector substrate, detector coatings, or optical coatings. Usually, they appear radially symmetric and extended in NISP images and may saturate the detector. They might be accompanied by showers or increased number of hot pixels or secondary hits in their immediate surrounding.
Observations¶
Fulfilled by¶
CALBLOCK-PV-012: NISP Dark Current and Snowballs
CALBLOCK-F-006: Wide Survey (from the slew darks)
Data volume¶
500*NP + 100*NS = 45800 MB
Processing input¶
Ground Processing Input Data: BPM, persistence masks
Data Description: 600 NISP science images
Processing method¶
Subtract the master dark from each individual dark. In the latter, identify very bright and extended detections, meaningful thresholds thereof will only be known from the observations themselves.
Processing output¶
Histograms of fluxes and FWHM of detected snowball events
Search for different flavors, that is snowballs with and without secondary showers.
Processing tools¶
L1 dark pipeline, trending statistics, histogram
Validation¶
None.
Recovery¶
None.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
NISP-P calibration scientist