GPU-Based Parallel Implementation of VLBI Correlator for Deep Space Exploration System

Fan Zhang,Chenxi Zhao,Songtao Han,Fei Ma,Deliang Xiang

doi:10.3390/rs13061226

Abstract

Very Long Baseline Interferometry (VLBI) solution can yield accurate information of angular position, and has been successfully used in the field of deep space exploration, such as astrophysics, imaging, detector positioning, and so on. The increase in VLBI data volume puts higher demands on efficient processing. Essentially, the main step of VLBI is the correlation processing, through which the angular position can be calculated. Since the VLBI correlation processing is both computation-intensive and data-intensive, the CPU cluster is usually employed in practical application to perform complex distributed computation. In this paper, we propose a parallel implementation of VLBI correlator based on graphics processing unit (GPU) to realize a more efficient and economical angular position calculation of deep space target. On the basis of massively GPU parallel computing, the coalesced access strategy and the parallel pipeline strategy are introduced to further accelerate the VLBI correlator. Experimental results show that the optimized GPU-based VLBI method can meet the real-time processing requirements of the received data stream. Compared with the sequential method, the proposed approach can reach a 224.1 × calculation speedup, and a 36.8 × application speedup. Compared with the multi-CPUs method, it can achieve 28.6 × calculation speedup and 4.7 × application speedup.

Highlights

The computational demands of scientific research are constantly increasing
In the field of radio astronomy, observation has evolved from the single telescope to the interferometer arrays, which is currently under development
Very Long Baseline Interferometry (VLBI) plays a key role in deep space exploration and astronomical observation due to the capability of high accurate angular measurement

Summary

Introduction

The computational demands of scientific research are constantly increasing. In the field of radio astronomy, observation has evolved from the single telescope to the interferometer arrays, which is currently under development. Interferometry (VLBI) technology, which increases the accuracy of observation by extending the distance between the stations, has been rapidly developed. They are all developed based on interferometric technology, but the data processing methods of them are different. The technology performs correlation calculations on the observation data of multiple radio telescopes, synthesizing multiple telescopes into a synthetic aperture telescope with an equivalent diameter of the longest baseline length [1,2]. With the increase of VLBI stations and the observation bandwidth, there is a strong demand for fast correlation processing [5,6]

Methods

Results

Conclusion