InSilicoLab for CTA

InSilicoLab for CTA offers a complete workspace for an Astrophysicitst who simulates the CTA telescopes with use of sim_telarray and read_hess programs. It is available to all Cherenkov Telescope Array consortium members with a Grid certificate registered in the CTA Virtual Organisation. The portal can be accessed from the CTA Science Gateway or directly through the link


Application-specific forms - depending on the chosen experiment (sim_telarray simulation or DST calculation), the input form contains fields suitable for the application used (sim_telarray or read_hess for the DST calculation). The forms provide suggestions for different program options.
Parameter sweep form - enables iterating over a set of values for a specified parameters while other values are constant.
Automatic parallelisation - in case the input data requires performing several computations, they are automatically configured and sent to a computing infrastructure. This will happen in two situations:

  • Multiple input shower files are specified manually,
  • A parameter sweep is configured.

Automatic results analysis - the sim_telarray computation results are automatically parsed with read_hess to extract relevant information:

  • Run number
  • ID of primary particle
  • Number of events, total
  • Number of events, triggered
  • Altitude (mean) [deg.]
  • Azimuth (mean) [deg.]
  • Cone (max) [deg.]
  • Lower limit of energy range [TeV]
  • Upper limit of energy range [TeV]
  • Spectral index in simulation
  • Spectral index in weighting
  • Weighted sum of events, total
  • Weighted sum of events, triggered
  • Maximum horizontal core distance in X
  • Maximum horizontal core distance in Y
  • Maximum core distance in shower plane
  • Supposed maximum core distance

The original application output files are also available for download Advanced computation options - optimization of the computation parameters on the e-Infrastructure - read more...



sim_telarray is a code used for simulation of arrays of Cherenkov telescopes. It allows to define different detectors with different read out, different triggering schemes or different reflectors. Simulations include optical ray-tracing, night-sky background, all relevant electronic pulse shapes, switching behaviour of comparators or discriminators.

read_hess software attempts to reconstruct events seen by the telescope by applying various image analysis methods, image cleaning etc.
eventdisplay is a software package for analysis of data from ground-based gamma-ray observatories like VERITAS and CTA. It was originally developed as display for the VERITAS prototype data, but evolved into a full analysis package with routines for calibration, FADC trace integration, image and stereo parameter analysis, response function calculation and high-level analysis steps (e.g. sky maps and spectral analysis). The original authors of eventdisplay are Jamie Holder and Gernot Maier.


Sim_telarray parameters configuration.

sim_telarray parameters configuration

Trigger Efficiency chart calculated for a set of different telescope array parameters.

Trigger Efficiency

PostScript DST file generated with read_hess



Video demonstrating simulations with sim_telarray.


See more videos...