Atmospheric multiple scattering of fluorescence and Cherenkov light emitted by extensive air showers

TL;DR

This paper introduces a Monte Carlo method to evaluate the impact of multiply scattered atmospheric light on fluorescence and Cherenkov signals from extensive air showers, improving the accuracy of optical shower observations.

Contribution

It presents a novel Monte Carlo simulation approach and parameterization for multiply scattered light, extending beyond previous models that only considered direct and singly scattered photons.

Findings

Multiply scattered light significantly affects observed air shower signals.

The new model improves the accuracy of fluorescence and Cherenkov light measurements.

Simulation results provide a basis for better data correction in air shower experiments.

Abstract

Atmospheric scattering of light emitted by an air shower not only attenuates direct fluorescence light from the shower, but also contributes to the observed shower light. So far only direct and singly-scattered Cherenkov photons have been taken into account in routine analyses of the observed optical image of air showers. In this paper a Monte Carlo method of evaluating the contribution of multiply scattered light to the optical air shower image is presented, as well as results of simulations and a parameterization of scattered light contribution to measured shower signal.