# The beamformer and correlator for the Large European Array for Pulsars

## TL;DR

This paper presents a software correlator and beamformer for the Large European Array for Pulsars, enabling high-sensitivity, coherent combination of data from multiple telescopes to improve pulsar observations for gravitational wave detection.

## Contribution

It introduces a novel software pipeline for coherently combining raw voltages from diverse telescopes, enhancing pulsar observation capabilities.

## Key findings

- Successful implementation of the software correlator and beamformer.
- Improved sensitivity in pulsar observations for gravitational wave detection.
- Effective handling of data from inhomogeneous, widely spaced telescopes.

## Abstract

The Large European Array for Pulsars combines Europe's largest radio telescopes to form a tied-array telescope that provides high signal-to-noise observations of millisecond pulsars (MSPs) with the objective to increase the sensitivity of detecting low-frequency gravitational waves. As part of this endeavor we have developed a software correlator and beamformer which enables the formation of a tied-array beam from the raw voltages from each of telescopes. We explain the concepts and techniques involved in the process of adding the raw voltages coherently. We further present the software processing pipeline that is specifically designed to deal with data from widely spaced, inhomogeneous radio telescopes and describe the steps involved in preparing, correlating and creating the tied-array beam. This includes polarization calibration, bandpass correction, frequency dependent phase correction, interference mitigation and pulsar gating. A link is provided where the software can be obtained.