.. index:: Spectroscopic small-scale flat (NISP)
   
.. _calobs-nisp-spec-small-scale-flats:

**CALPRODUCT-NS-005:** NISP-S Small-Scale Flat
==============================================

.. include:: definitions.rst

Parent requirement
------------------
| `R-CAL-B-NS-2110 <https://wiki.cosmos.esa.int/euclid/images/1/1d/EUC-MPIA-RD-1-001_CalCD-B_v3.1.pdf#page=77>`_
| `R-CAL-B-NS-2120 <https://wiki.cosmos.esa.int/euclid/images/1/1d/EUC-MPIA-RD-1-001_CalCD-B_v3.1.pdf#page=77>`_

Scheduling
----------
Monthly

Time-critical
-------------
No

Dependencies
------------
None

Objective
---------
Reconstruct matching spectroscopic small-scale flat fields for all four grisms from the :ref:`calobs-nisp-led-flats`.

Fulfilled by
------------

:ref:`calobs-block-pv-nisp-LED`

:ref:`calobs-block-f-visNL-nispLED`

Data volume
-----------
TBD

Processing input
----------------
:command:`Ground Processing Input Data`: BPM, ground-based QE

:command:`Data Description`: Flat-field and QE cubes


Processing method
-----------------
Using the ground-based quantum efficiency (QE) maps, a generic flat-field cube is built. By integrating the cube over the full throughput, i.e. telescope (PLM), instrument optics (NI-OA) and grism transmission, effective flat fields are obtained for all grisms.

Processing output
-----------------
Effective flat fields for all grisms. Trend analysis.

Required accuracy, constraints
------------------------------
Expected flux levels within TBD%, stable within TBD%, spatial irradiance as expected (within requirement, ground-based measurements)

Processing tools
----------------
L1 small scale flat pipeline, trending statistics, offline analysis for trapping/de-trapping, persistence

Quality control parameters
--------------------------
DataModel:
`<https://gitlab.euclid-sgs.uk/>`_

Contact person
--------------
NISP-S calibration scientist  

.. raw:: latex

   \clearpage