Nanosecond-level time synchronization of AERA using a beacon reference transmitter and commercial airplanes

TL;DR

This paper presents a method to achieve nanosecond-level time synchronization of cosmic-ray detectors using a beacon transmitter and commercial airplane signals, improving accuracy beyond GPS alone.

Contribution

It introduces a combined timing correction approach using a beacon reference and airplane radio pulses for enhanced synchronization accuracy.

Findings

Timing accuracy better than 2 nanoseconds achieved

Beacon correction effectively compensates for clock drifts

Method improves cosmic-ray air shower reconstruction precision

Abstract

Radio detection of cosmic-ray air showers requires time synchronization of detectors on a nanosecond level, especially for advanced reconstruction algorithms based on the wavefront curvature and for interferometric analysis approaches. At the Auger Engineering Radio Array, the distributed, autonomous detector stations are time-synchronized via the Global Positioning System which, however, does not provide sufficient timing accuracy. We thus employ a dedicated beacon reference transmitter to correct for event-by-event clock drifts in our offline data analysis. In an independent cross-check of this "beacon correction" using radio pulses emitted by commercial airplanes, we have shown that the combined timing accuracy of the two methods is better than 2 nanoseconds.