November 3, 2015 Calibration Challenge

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GlueX Calibration Meeting
Tuesday, November 3, 2015
1:30 pm, EST
JLab: CEBAF Center, F326

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  1. Calibration Challenge
    • Discussion


Attending: Sean, Simon, Mark I., Justin, Elton, Alex B., Zisis, Will M., Mike S.

Sean laid a rough plan for the challenge, and it was discussed extensively. Some relevant notes:

  • Useful things we expect to get out of this exercise include:
    • Understanding of the dependencies of the calibrations
    • More robust, well-defined procedures
    • Better validation
  • We decided to focus on the "type 1" challenge, which involves deriving constants from one run of beam data
    • Other challenges could be defined at a later stage
  • The process will involve several "passes" through the EVIO data to refine the calibrations
    • No user-intervention is forseen at any point. Sean (and others) will help work with people that have a defined calibration procedure to automate the work and adapt it to this data flow
  • Calibrations will be stored in CCDB after each pass in a dedicated variation
    • Multiple variations could be used
    • SQLite or MySQL?
  • Information should be passed by ROOT histograms, if possible
    • Results will be saved after each pass
  • Monitoring / validation of constants is important
    • A validation step will be the last stage run
    • Finally, tools to compare the derived constants with current values and to potentially submit these constants will be developed
  • Mike shared his experiences with automated timing calibrations, including the interlocking nature of the calibrations, the importance of standards, careful attention to little details like those of binning.
    • Mike and Paul M.'s calibration ROOT scripts have some nice code snippets other authors can use, including code to pull calibration constants from CCDB into the script
  • The list of calibrations to run was updated

Going forward:

  • Subdetector groups will define the neutral starting values for each of the tables involved in this exercise
  • Sean will work with the authors of the calibration procedures to define a dependency tree and to move their code into sim-recon
  • Sean will continue to develop test jobs - next meeting we will look at their output
  • We will meet again next week to continue to develop plans