Reconstructing inclined extensive air showers from radio measurements

TL;DR

This paper introduces a radio-based reconstruction algorithm for inclined extensive air showers, achieving high efficiency and sub-5% energy resolution, suitable for large-scale cosmic ray detection arrays.

Contribution

The paper presents a novel reconstruction algorithm based on a signal model from CoREAS simulations that accounts for asymmetries and correlations, improving stability and accuracy.

Findings

Near 100% reconstruction efficiency

Electromagnetic energy resolution below 5%

Applicable to large-scale radio detection arrays

Abstract

We present a reconstruction algorithm for extensive air showers with zenith angles between 65$^\circ$ and 85$^\circ$ measured with radio antennas in the 30-80 MHz band. Our algorithm is based on a signal model derived from CoREAS simulations which explicitly takes into account the asymmetries introduced by the superposition of charge-excess and geomagnetic radiation as well as by early-late effects. We exploit correlations among fit parameters to reduce the dimensionality and thus ensure stability of the fit procedure. Our approach reaches a reconstruction efficiency near 100% with an intrinsic resolution for the reconstruction of the electromagnetic energy of well below 5\%. It can be employed in upcoming large-scale radio detection arrays using the 30-80 MHz band, in particular the AugerPrime Radio detector of the Pierre Auger Observatory, and can likely be adapted to experiments such as GRAND operating at higher frequencies.