.. index:: CTI-induced covariance (VIS); Calibration observations
   
.. _calobs-block-pv-vis-cti-covariance:

**CALBLOCK-PV-030:** VIS CTI-induced covariance
===============================================

.. include:: definitions.rst

Observation configuration file
------------------------------
| :download:`ocf_CALBLOCK-PV-030.csv <tables/OCFs/ocf_CALBLOCK-PV-030.csv>`

Scheduling
----------
Once, during PV phase.

In case of failure, repeat at next possible opportunity.

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

Dependencies
------------
VS-CU commissioned

Objective
---------

Obtain the CTI-induced covariance map.

Observations
------------

Observe 20 flat field pairs at low fluences of 25, 50 and 100 ADU, each, with LED3. Bias pairs are mandatory, to correct for the Bias covariance. To neutralize AOCS wait times, and to accommodate antenna repointing, the following strategy is foreseen:

.. code-block::  none
   :caption: Dithered flat field pairs (LED3) for CTI covariance. SS means a VIS short science exposure.

   for fluence in [25, 50, 100 ADU]:
      Repeat 2x:
         2x BIAS, 4x FLAT, SS, dither
         6x FLAT, SS, dither

Fulfilling
----------

:ref:`calobs-vis-cti-covariance`
     
Targets and pointing constraints
--------------------------------

:command:`Pointing`: Straylight suppression as per MOCDA-SYS-003. 

.. csv-table:: SELFCAL-FAINT :download:`CSV file <tables/targets-selfcal-faint.dat>`
   :widths: 15, 8, 8
   :file: tables/targets-selfcal-faint.dat

Instrument configuration
------------------------

Instrument: VS-CU on

Methodology / Uplink procedure
------------------------------
:command:`Entity`: VIS

:command:`Commanding Method`: VIS:

:command:`Dither Sequence`: Random dither offsets in 3' box

Inter-operability constraints
-----------------------------
None.

In-orbit duration
-----------------

:command:`In-orbit Duration`: 7.4 h + dither (x12)

Note that 66s of the CDPU processing time has been absorbed into the dither/slew duration.

	 
Data volume
-----------

``(2*VB + 10*VF + 2*VS)*6 = 32424 MB``  (``VF=400 MB``)

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

:command:`Data Description`: Per fluence 20 flats, 4 biases, 4 short science

Processing output
-----------------
Covariance per detector quadrant.

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

Contact person
--------------
VIS instrument scientist  

.. raw:: latex

   \clearpage