2019/03/18 by Pratley, Luke, McEwen, Jason D.
#FOS: Physical sciences #Instrumentation and Methods for Astrophysics (astro-ph.IM)
paper · doi:10.48550/arxiv.1903.07621
We present a new algorithm to perform wide-field radio interferometric image reconstruction, with exact non-coplanar correction, that scales to big-data. This algorithm allows us to image 2 billion visibilities on 50 nodes of a computing cluster for a 25 by 25 degree field of view, in a little over an hour. We build on the recently developed distributed w-stacking w-projection hybrid algorithm, extending it to include a new distributed degridding algorithm that balances the computational load of the w-projection gridding kernels. The implementation of our algorithm is made publicly available in the PURIFY software package. Wide-field image reconstruction for data sets of this size cannot be performed effectively using the allocated computational resources without computational load balancing, demonstrating that our algorithms are critical for next-generation wide-field radio interferometers.