Post-Correlation RFI Excision at Low Frequencies
W. Lane (Naval Research Laboratory) wendy.lane@nrl.navy.mil
A. Cohen (Naval Research Laboratory) aaron.cohen@nrl.navy.mil
N. Kassim (Naval Research Laboratory) namir.kassim@nrl.navy.mil
J. Lazio (Naval Research Laboratory) joseph.lazio@nrl.navy.mil
R. Perley (National Radio Astronomy Observatory) rperley@nrao.edu
B. Cotton (National Radio Astronomy Observatory) bcotton@nrao.edu
E. Greisen (National Radio Astronomy Observatory) egreisen@nrao.edu

We describe some RFI excision schemes which are currently being used in low frequency (<1 GHz) radio astronomy. We present examples from our experience with editing of single dish and interferometric data, and discuss specialized procedures employed for targetted observations, as well as broader brush, pipe-line schemes developed for surveys such as the VLA Low Frequency Sky Survey (VLSS). We will elaborate on the strengths and weaknesses of currently employed procedures, with an eye to providing useful guidance to those developing future, more sophisticated post-detection data editing algorithms. Our experience with RFI excision below 1 GHz should be of interest in the context of future SKA studies of Dark Energy and the Epoch of Reionization, as well as the development of other low frequency instruments such as the LWA and LOFAR.