CALBLOCK-F-018: NISP Persistence¶
Observation configuration file¶
Scheduling¶
In the monthly block between CALBLOCK-F-001: Self Calibration and CALBLOCK-F-007: VIS Nonlinearity, PTC, BFE and NISP LED flats. Like this it does not affect self-calibration, and any residual persistence from the NISP LED flats in F-007 does not bias the measurement of the persistence parameters. Also, the darks from subsequent F-007 provide sufficient persistence decay before survey operations resume.
In case of failure, continue with the survey plan.
Objective¶
We found considerable time variability of the persistence coefficients, and that the single PV calibration in CALBLOCK-PV-016: NISP Persistence is insufficient. Monthly observations are required to update the parameters for persistence correction.
Observations¶
There is a small dependence of the persistence parameters on the incident flux (on the order of a 10% change) as long as the detectors are not saturated. Thus we use a single LED fluence of 30 kADU (above the baseline level), followed by a series of short and long darks. LED ‘E’ is used for all persistence tests. We also take 3 trash darks at the beginning to allow for some persistence decay from the preceding on-sky observations.
Insert HGA repointings as necessary
Take 3x MACC(4,16,4) trash darks
Repeat 2x:
Turn on LED 'E', fluence 30 kADU (690 e-/s)
Take 1 flat field with MACC(4,16,4)
Turn off LED
Take 5 photo-MACC darks
Take 4 spectro-MACC darks
# Fluence [kADU] |
Flux [e-/s] |
Flux [ADU/frame] |
Int [mA] |
PWM [%] |
10 |
230 |
167.3 |
10.0 |
19.8 |
20 |
460 |
334.6 |
10.0 |
37.4 |
30 |
690 |
501.9 |
30.0 |
14.6 |
40 |
920 |
669.2 |
30.0 |
18.4 |
50 |
1150 |
836.5 |
30.0 |
22.3 |
Fulfilling¶
Targets and pointing constraints¶
Pointing: off-sky observation. Straylight suppression as per MOCDA-SYS-003.
Instrument configuration¶
Instrument: NI-CU on, NI-CU off
Methodology / Uplink procedure¶
Entity: NISP
Commanding Method: NISP: Observation
Dither Sequence: None
Inter-operability constraints¶
None
In-orbit duration¶
In-orbit Duration: 1.8 h
3*111s + (111s+5*111s+4*565s)*2 = 1.8 h
Data volume¶
Total: 6129 MB
15*NP + 8*NS = 2189 MB
Processing input¶
Ground Processing Input Data: Darks (without persistence)
Data Description: 2 flat fields, 10 photo-MACC darks, 8 spectro-MACC darks
Required accuracy, constraints¶
Must be able to evaluate the persistence signal per pixel.
Validation¶
Update the time constants and amplitudes.
Recovery¶
None. Just continue with the survey plan.
Quality control parameters¶
DataModel: https://gitlab.euclid-sgs.uk/
Contact person¶
NISP-P calibration scientist