English

A morphological algorithm for improving radio-frequency interference detection

Instrumentation and Methods for Astrophysics 2012-03-01 v2

Abstract

A technique is described that is used to improve the detection of radio-frequency interference in astronomical radio observatories. It is applied on a two-dimensional interference mask after regular detection in the time-frequency domain with existing techniques. The scale-invariant rank (SIR) operator is defined, which is a one-dimensional mathematical morphology technique that can be used to find adjacent intervals in the time or frequency domain that are likely to be affected by RFI. The technique might also be applicable in other areas in which morphological scale-invariant behaviour is desired, such as source detection. A new algorithm is described, that is shown to perform quite well, has linear time complexity and is fast enough to be applied in modern high resolution observatories. It is used in the default pipeline of the LOFAR observatory.

Keywords

Cite

@article{arxiv.1201.3364,
  title  = {A morphological algorithm for improving radio-frequency interference detection},
  author = {A. R. Offringa and J. J. van de Gronde and J. B. T. M. Roerdink},
  journal= {arXiv preprint arXiv:1201.3364},
  year   = {2012}
}

Comments

Accepted for publication in A&A

R2 v1 2026-06-21T20:05:20.189Z