Fast Radio Burst Search: Cross Spectrum vs. Auto Spectrum Method

TL;DR

This paper compares auto spectrum and cross spectrum methods for fast radio burst detection in VLBI data, demonstrating that the cross spectrum approach better enhances signals amidst RFI contamination, enabling more effective FRB searches.

Contribution

It introduces a comparison between auto and cross spectrum methods for FRB search, highlighting the advantages of the cross spectrum approach in RFI-rich environments.

Findings

Cross spectrum method enhances signal power in RFI-contaminated data.

Cross spectrum method enables FRB search in regular VLBI observations.

Auto spectrum method is less effective under high RFI conditions.

Abstract

The search of fast radio burst (FRB) is a hot topic in current radio astronomy study. In this work, we carry out single pulse search for a VLBI pulsar observation data set using both auto spectrum and cross spectrum search method. The cross spectrum method is first proposed in Liu et al. (2018), which maximizes the signal power by fully utilizing the fringe phase information of the baseline cross spectrum. The auto spectrum search method is based on the popular pulsar software package PRESTO, which extracts single pulses from the auto spectrum of each station. According to our comparison, the cross spectrum method is able to enhance the signal power and therefore extract single pules from highly RFI contaminated data, which makes it possible to carry out FRB search in regular VLBI observations with the presence of RFIs.