Mulitbeam GPU Transient Pipeline for the Medicina BEST-2 Array

TL;DR

This paper introduces a real-time GPU-based multi-beam transient detection pipeline for radio telescopes, demonstrating its effectiveness at the Medicina BEST-2 array with scalable processing capabilities for astrophysical transient signals.

Contribution

It presents a novel GPU-accelerated pipeline capable of processing multiple radio beams simultaneously for transient detection, including RFI rejection, dedispersion, and event clustering.

Findings

Processed 8 beams simultaneously at 20MHz each

Capable of handling ~640 DM values in real-time

Scalable architecture increases with more servers and GPUs

Abstract

Radio transient discovery using next generation radio telescopes will pose several digital signal processing and data transfer challenges, requiring specialized high-performance backends. Several accelerator technologies are being considered as prototyping platforms, including Graphics Processing Units (GPUs). In this paper we present a real-time pipeline prototype capable of processing multiple beams concurrently, performing Radio Frequency Interference (RFI) rejection through thresholding, correcting for the delay in signal arrival times across the frequency band using brute-force dedispersion, event detection and clustering, and finally candidate filtering, with the capability of persisting data buffers containing interesting signals to disk. This setup was deployed at the BEST-2 SKA pathfinder in Medicina, Italy, where several benchmarks and test observations of astrophysical transients were conducted. These tests show that on the deployed hardware eight 20MHz beams can be processed simultaneously for $\sim$640 Dispersion Measure (DM) values. Furthermore, the clustering and candidate filtering algorithms employed prove to be good candidates for online event detection techniques. The number of beams which can be processed increases proportionally to the number of servers deployed and number of GPUs, making it a viable architecture for current and future radio telescopes.