Introduction

Note

This is only a (very) short introduction into the SnowStorm simulation approach focusing on “how to run it”. Please refer to the SnowStorm paper for a detailed description of the method.

How it Works

In order to variate systematic parameters, Snowstorm depends on a parametrization that transform a (sampled) parameter vector x into frame objects which hold the corresponding settings/values for CLSim. Different parametrizations for different systematic parameters can be added to a so called “perturber”. The perturber then gets applied in the photon propagation step in the simulation. It samples a parameter (vector) for each parametrization according to their (individual) sampling distribution and calls the transform method to transform the parameter (vector) x into frame objects. These frame objects are then read by CLSim which uses the corresponding settings for e.g. DOMEfficiency or ice-scattering.

For bookkeeping, the sampled parameter vector x, the (serialized) sampling distributions and the names of the parametrizations get stored in an extra frame by the perturber (when getting applied).

SnowStorm Simulation Chain

The overall simulation chain is very similar to the default, “non-SnowStorm” one:

  1. Event (signal) generation (1-process-Gen.py)

    1.1 CR background simulation

  2. Merging CR background using polyplopia (2-Polyplopia.py) To ensure that the CR background is treated in the exact same way as the signal simulation (i.e. with the same, perturbed ice model parameters), it is just merged here. All particle propagation, including running PROPOSAL, is done in the next step.

  1. Photon propagation with application of the SnowStorm perturber (3-Snowstorm.py) (includes running PROPOSAL)

  2. Detector simulation

  3. Level1 processing

  4. Level2 processing

Steps 3 to 5 are not different to the “non-SnowStorm” simulation chain. The scripts for steps 1 to 3 can be found in the SnowSuite script collection.

Details on how to run 3-Snowstorm.py and how to configure the perturber with parametrizations (see SnowStorm Parametrizations) can be found in SnowsStorm Configuration.