.. index:: Bad Pixel Map (NISP) .. _calobs-nisp-badpixmap: **CALPRODUCT-NI-001:** NISP Bad Pixel Map ========================================= .. include:: definitions.rst Parent requirement ------------------ R-NIP-P-006 in the PERD Scheduling ---------- Continuously updated. Time-critical ------------- No. Dependencies ------------ :ref:`calobs-nisp-darks` :ref:`calobs-nisp-led-flats` :ref:`calobs-nisp-baseline` Objective --------- The purpose of this task is to update the bad pixel map (BPM) on a regular basis. There is no dedicated set of observations associated with this task. The bad pixel map is derived from secondary ``CalProducts``, obtained both on-ground (e.g. permanently disconnected pixels) and in-flight. Both intermittent and permanent bad pixels enter the BPM. Currently, the BPM is based on the baseline maps, dark current and flat field. New dead pixels, high/low baseline, and permanently hot pixels will be identified in :ref:`calobs-nisp-darks`. Monitoring for bad pixels can also be done using :ref:`calobs-nisp-slewdarks`. In total, there are 5 PEs that currently build the BPM. A robust definition of hot pixels is still pending. **Snowballs** inject a lot of energy; some are recurrent, others are randomly distributed. There is currently no calibration product for them. **Random telegraph noise (RTN)** pixels can be identified in flat fields, but are currently not covered by processing. **Anomalous nonlinearity** and **high persistence** are currently not entering the BPM. Pixels that currently carry a persistence signal are masked anyway during the survey if beyond a threshold. Fulfilled by ------------ Different data products contribute to the bad-pixel map. :ref:`calobs-block-pv-nisp-LED` :ref:`calobs-block-pv-nisp-darks` :ref:`calobs-block-pv-nisp-baseline` :ref:`calobs-block-f-wide-survey` (providing the slew darks) :ref:`calobs-block-f-visNL-nispLED` Instrument configuration ------------------------ Instrument: NISP Processing input ---------------- * Static bad pixel map (dead, disconnected, hot) * Dark current map (warm and hot pixels) * Baseline map (pixels with limited dynamic range due to high bias level) * LED flat fields .. index:: Random Telegraph Noise (RTN) * Pixels with high random telegraph noise (RTN, currently not captured). :command:`Ground Processing Input Data`: Dark, nonlinearity, small-scale flat, persistence map, static bad pixel map :command:`Data Description`: Processing output ----------------- Updated BPM. Monitoring of the total fraction of bad pixels, as well as the fractions of the individual contributors. Validation ---------- R-NIP-P-006 and R-NIS-P-016 in EUCL-EST-RD-3-002_v2.2_PERD (PERD) allow a lost pixel budget of 10\%. Internally, this is broken down into transients (3\% for cosmics, 1\% for persistence from previous exposures), 5% for static and dynamic bad pixels, and 1% margin. The BPM of this ``CalProduct`` concerns about the static and dynamic bad pixels, only. The BPM shall not mask more than 5\% of all pixels. Recovery -------- If more than 5% of pixels are masked by the BPM, the underlying contributors and causes shall be identified. We highlight two possible scenarious: First, a single ``CalProduct`` entering the BPM causes excess masking. This could indicate a failure in the validation of that specific ``CalProduct``. The validation criteria, monitoring analysis and thresholding of this ``CalProduct`` must be revisited. For example, it might have been taken during increased solar proton flux levels, and an adjustment of the allowed threshold is required or a change of procedures in order. The invalid ``CalProduct`` shall be replaced by a previous, valid version. Second, several ``CalProducts`` contribute increased amounts of bad pixels, none of them individually at a level that would raise a concern during its validation. This could happen e.g. towards the end of the mission, when radiation damages accumulate. Quality control parameters -------------------------- DataModel: ``_ Contact person -------------- NISP-P calibration scientist .. raw:: latex \clearpage