# Introduction

Detailed and precise MC modelling of the detection process is the basis
for any scientific analysis in ground-based gamma-ray astronomy. This
requires a realistic model of the atmospheric conditions and all
detector components. The MC tools aim to describe the
[CTA]{acronym-label="CTA" acronym-form="singular+short"} telescopes in
sufficient detail, taking into account the required precision and
computing constrains.

This document is part of a series of reports written to support the CTA
Pre-Production Design and Deployment Acceptance Plan [@PPDDA]. The
process is described in detail, including all the required documentation
and verification points, in Ref. [@verMC]. The goal of this process is
to verify the consistency between telescope specifications and the
models implemented in the CTA simulations framework for telescope light
collection, photon detection, electronics and signal processing. The
verification process is defined with the following steps [@verMC]:

1.  A list of relevant input parameters, as well as a list describing
    the relevant algorithms, will be prepared by the AS-WG and
    distributed to each telescope WP.

2.  Each WP will match these to their list of performance-relevant
    telescope specifications and identify missing parameters and/or
    algorithms.

3.  The AS-WG will identify missing specifications needed for high
    fidelity performance simulation and iterate with each WP to arrive
    at an agreed mapping of parameters to specifications. Each WP is
    obligated to provide the missing information and algorithms
    identified by the AS-WG.

4.  The AS-WG and WP will work together to check each item in the list,
    and independently confirm that the simulation description of that
    element is adequate for the needs of design compliance verification.

This document is part of step 1 and provides a description of the MC
model including all parameters and relevant algorithms. It concentrates
on the CTA simulation framework as used in the large-scale MC simulation
productions (e.g. prod3), consisting of the software packages CORSIKA
and  [@Bernlohr:2008kv].

Similar reports are written for all telescope types: LST, MST-FlashCam,
MST-NectarCam, MST-Structure, MST-SC, SST-1M, ASTRI, GCT. Where
necessary, different reports are produced for pre-design and prototype
configurations.

# Table of Contents

```{toctree}
:maxdepth: 1
Descriptions <descriptions/index.md>
Model Versions <model_versions/index.md>
```