We present a procedure for efficiently compressing astronomical radio data for high performance applications. Integrated, post-correlation data are first passed through a nearly lossless rounding step which compares the precision of the data to a generalized and calibration-independent form of the radiometer equation. This allows the precision of the data to be reduced in a way that has an insignificant impact on the data. The newly developed Bitshuffle lossless compression algorithm is subsequently applied. When the algorithm is used in conjunction with the HDF5 library and data format, data produced by the CHIME Pathfinder telescope is compressed to 28% of its original size and decompression throughputs in excess of 1 GB/s are obtained on a single core.
@article{arxiv.1503.00638,
title = {A compression scheme for radio data in high performance computing},
author = {Kiyoshi Masui and Mandana Amiri and Liam Connor and Meiling Deng and Mateus Fandino and Carolin Höfer and Mark Halpern and David Hanna and Adam D. Hincks and Gary Hinshaw and Juan Mena Parra and Laura B. Newburgh and J. Richard Shaw and Keith Vanderlinde},
journal= {arXiv preprint arXiv:1503.00638},
year = {2015}
}
Comments
12 pages, 3 figures, 2 tables. As published in Astronomy and Computing special issue on "The future of astronomical data formats"