We describe the design and implementation of an extremely scalable real-time RFI mitigation method, based on the offline AOFlagger. All algorithms scale linearly in the number of samples. We describe how we implemented the flagger in the LOFAR real-time pipeline, on both CPUs and GPUs. Additionally, we introduce a novel simple history-based flagger that helps reduce the impact of our small window on the data. By examining an observation of a known pulsar, we demonstrate that our flagger can achieve much higher quality than a simple thresholder, even when running in real time, on a distributed system. The flagger works on visibility data, but also on raw voltages, and beam formed data. The algorithms are scale-invariant, and work on microsecond to second time scales. We are currently implementing a prototype for the time domain pipeline of the SKA central signal processor.
Cite
@article{arxiv.1701.08197,
title = {Towards exascale real-time RFI mitigation},
author = {Rob V. van Nieuwpoort},
journal= {arXiv preprint arXiv:1701.08197},
year = {2017}
}
Comments
2016 Radio Frequency Interference (RFI2016) Coexisting with Radio Frequency Interference, Socorro, New Mexico, USA, October 2016