Disabling Calibration Constants
===============================

Sometimes it turns out that faulty calibration parameters have been injected.
In this case disabling the relevant constant versions will assure that future
correction tasks (both online and offline) will not use these parameters
anymore.

.. warning::

    This procedure can have severe impact on detector calibration. Only
    proceed if you know what you are doing!


Screencast of Procedure
-----------------------

.. figure:: gen_cal_db_disable_constants.gif

    How to disable calibration constants in
    `the database backend <https://in.xfel.eu/calibration/>`_.


Step by Step Instructions
-------------------------

Disabling is done via the calibration database backend.

1. Navigate to `the database backend <https://in.xfel.eu/calibration/>`_ and
   log in using your normal LDAP credentials. For the following steps you
   will need elevated access rights, which can be requested at
   `det-support@xfel.eu`.

   .. figure:: cal_db_login.png

      Logging into the calibration database backend

2. After logging in, navigate to the `Admin` area, and here to
   `Calibration constant versions`. This will list you the latest
   calibration parameters injected into the database.

   .. figure:: cal_db_versions.png

      The calibration database version overview. Setting a filter is
      highlighted.

3. You should now apply filters to find the faulty constants. It is usually
   most appropriate to filter by `Physical device` and `Start date`.
   The `Physical device` filter is fuzzy; hence entering e.g. AGIPD will
   list all AGIPD modules.

   The `Start date` filter will usually match when the data used for
   characterization was taken.


   .. figure:: cal_db_set_versions.png

      Setting filter options on the calibration constant version page and
      selecting versions to disable

4. After having located the faulty parameters you need to disable them. For
   Dark image derived constants usually come in triplets: Noise, Offset, and
   Bad Pixels, or for AGIPD additionally with Thresholds. You should disable
   each one, by clicking on the pen symbol at the far right and editing
   the constant version in a new tab.


   .. figure:: cal_db_edit_version1.png

      The edit calibration constant version dialog.

5. On the edit page, scroll to the bottom and uncheck the two boxes labelled
   `deployed` and good quality`. Then click save.

    .. figure:: cal_db_edit_version2.png

      Disabling deployed and good quality markers for a constant version.


6. Refreshing the filtered calibration constant version view should now
   list these calibration parameters as disabled.

   .. figure:: cal_db_undeployed.png

      Disabled versions in the overview.