An example of FAST data for RFI detection and its labelled mask. (b) The computational results based on the procedures in Section 3.2.2 for band RFI. (c) The result after flagging both band RFI and blob RFI using the ArPLS-ST method. The result in (b) is blacker than in (c) because the blob RFI with higher intensity has not been removed in the former.