ReconstructionDetails < DetDev

---+ Testbeam Reconstruction Details

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Installation: http://eutelescope.web.cern.ch/content/installation

After installing and sourcing environment (build_env.sh) the main directory is $EUTELESCOPE

Useful directories
   * src (include): contains processor source code (headers)
   * build: recompilation after code changes
      * <code> > cmake .. </code>
      * <code> > make install </code>
   * jobsub: includes examples folder with template reconstructions
   * pixgeo: where geometry files for sensor libraries are stored
   * external: includes eudaq code

---++ Working Folder

In working folder: $EUTELESCOPE/jobsub/examples/SOME_EXAMPLE
   * Steering folder: Steering files for each reconstruction step. Each file contains list of Processors executed in the step
   * Configuration file: Specifies user directories: data directory, output directories
      * general parameters: number of events, output frequency
      * steering parameters: specific to each reconstruction step
   * Gear file: Specifies devices and physical positions/orientations of set-up
   * Runlist file: Parameters specific to particular runs
   * Output directories: Store histograms and hit sets form each reconstruction step

OUTPUT DIRECTORIES

These are specified in the config file.

In working folder: $EUTELESCOPE/jobsub/examples/SOME_EXAMPLE/output
   * histograms: Root files with distribution plots produced in reconstruction step
   * lcio: Input/output collections used by EUTelescope and passed between steps
   * database: Parameters used by the reconstruction
   * logs: Log files for each jobsub execution

Each file has standard prefix (set in config): runXXXXXX
   * XXXXXX is run number specified on execution -always six digits

RECONSTRUCTION STEPS:

There are five basic steps to run the reconstruction chain (i.e. to transform raw data into analysis ready data):
   * converter: Read in telescope and DUT hit information, from native DAQ to LCIO format
   * clustering: Combine individual hits on each plane to hit clusters on each plane
   * hitmaker: Globally orient planes
   * align: Global alignment of planes: based on pattern recognition & track fitting
   * fitter: Generate tracks --&gt; device resolution

Parameters used in each reconstruction step are defined between config, runlist and steering files: config includes global parameters; runlist includes run specific parameters; and, gear file has the sensor specification. Other values can be found in the individual steering files, though any non-global values can be defined elsewhere. Parameters are refered to across files using <code>@NAME@</code> syntax.

Other steps are definable in the steering directory. All follow the form of a recipe of processors (in execution order) with processor definitions below (no order required). The source coude for each processor can be found in $EUTELESCOPE/src (include) by identifying the processor "type" specified at the top of each processor definition in the steering file.

The basic steps are expanded on below.

---++++ Converter

Two functions
   * Decode raw files: telescope plane and DUT hit information
      * Translated into LCIO hits (format of EUTELESCOPE), Uses eudaq to convert from native format.
      * Converter file found in: $EUTELESCOPE/external/eudaq/&lt;version&gt;/main/lib/src
   * check for hot pixels -&gt; create list for masking later

REQUIRES:
   * Specification of planes: gear file & steering file
      * Plane names (i.e. numbers) to expect
      * Correct specification of devices (# detector elements) in gear file
   * Library of detector geometry required

SET:
   * Config: Max Firing Frequency – identify hot pixels

OUTPUT:
   * OUTPUTPATH/histograms/runXXX-converter-histo.root
   * OUTPUTPATH/database/runXXX-hotpixel-m26-db.slcio
   * OUTPUTPATH/lcio/runXXX-converter.slcio

Check noisy pixels from histograms

---++++ Clustering

Combine hit pixels in proximity into clusters

Alternative methods:
   * Clustering: pixel based clustering
   * Geoclustering: geometry based clustering

REQUIRES:
   * OUTPUTPATH/lcio/runXXX-converter.slcio
   * Gear file for pitch parameter ( geometric clustering only)

OUTPUT:
   * OUTPUTPATH/histograms/runXXX-clustering-histo.root
   * OUTPUTPATH/lcio/runXXX-clustering-histo.root

Check device response from cluster plots.

Standard: signal, total size, sizeX, sizeY, multiplicity

---++++ HITMAKER

Globally orient planes.

Alternative methods:
   * Clustering: pixel based clustering
   * Geoclustering: geometry based clustering

REQUIRES:
   * Specification of plane orientation: gear file
   * OUTPUTPATH/lcio/runXXX-clustering.root

SET:
   * Config: Specify cuts around hit peaks for pre-alignment

OUTPUT:
   * OUTPUTPATH/histograms/runXXX-hitmaker-histo.root
   * OUTPUTPATH/database/runXXX-refhit-db.slcio
   * OUTPUTPATH/database/runXXX-prealign-db.slcio
   * OUTPUTPATH/lcio/runXXX-hitmaker-histo.root

Check success in correlation plots (bottom-left to top-right strip)

---++++ ALIGN

Global alignment of planes: based on pattern recognition & track fitting

SET:
   * Config: Specify resolution cuts around hits

REQUIRES:
   * OUTPUTPATH/lcio/runXXX-hitmaker.root

OUTPUT:
   * OUTPUTPATH/histograms/runXXX-align-histo.root
   * OUTPUTPATH/lcio/runXXX-align-histo.root
   * OUTPUTPATH/database/runXXX-alignment.slcio

Check success in chi2 distribution

---+++++ FITTER

Generate tracks -&gt; device resolution

SET:
   * Config: Specify resolution cuts around hits

REQUIRES:
   * OUTPUTPATH/lcio/runXXX-hitmaker.root
   * OUTPUTPATH/lcio/runXXX-align.root

OUTPUT:
   * OUTPUTPATH/histograms/runXXX-fitter.slcio
   * OUTPUTPATH/lcio/runXXX-track.slcio

Check success in chi2 distribution

---+++ BEWARE

Don’t source build environment more than once

Remember to recompile (update cmake) after changing source code

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-- %USERSIG{KennyWraight - 2015-04-21}%

---++ Comments

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This topic: DetDev > WebHome > EUTelescopeAndIBLTestbeam > ReconstructionDetails
Topic revision: r1 - 2015-04-21 - KennyWraight