  As radio telescopes become sensitive, radio frequency interference (RFI) is
more and more serious for interesting signals of radio astronomy. There exist
demands for developing an automatic, accurate and efficient RFI mitigation
method. Therefore, this work investigated the RFI detection algorithm. Firstly,
we introduced an Asymmetrically Reweighted Penalized Least Squares (ArPLS)
method to estimate baseline more accurately. After removing the estimated
baseline, several novel strategies were proposed based on the SumThreshold
algorithm for detecting different types of RFI. The threshold parameter in the
SumThreshold can be determined automatically and adaptively. The adaptiveness
is essential for reducing human interventions and the online RFI processing
pipeline. Applications to FAST (Five-hundred-meter Aperture Spherical
Telescope) data show that the proposed scheme based on the ArPLS and
SumThreshold is superior to some typically available methods for RFI detection
with respect to efficiency and performance.
