  Radio Frequency Interference (RFI) greatly reduces sensitivity of radio
observations to astrophysical signals and creates false positive candidates in
searches for radio transients. Real signals are missed while considerable
computational and human resources are needed to remove RFI candidates. In the
context of transient astrophysics, this makes effective RFI removal vital to
effective searches for fast radio bursts and pulsars. Radio telescopes
typically sample at rates that are high enough for there to be tens to hundreds
of samples along the transient's pulse. Mitigation techniques should excise RFI
on this timescale to account for a changing radio frequency environment. We
evaluate the effectiveness of three filters, as well as a composite of the
three, that excises RFI at the cadence that the data are recorded. Each of
these filters operates in a different domain and thus excises as a different
RFI morphology. We analyze the performance of these four filters in three
different situations: (I) synthetic pulses in Gaussian noise; (II) synthetic
pulses injected into real data; (III) four pulsar observations. From these
tests, we gain insight into how the filters affect both the pulse and the noise
level. This allows use to outline which and how the filters should be used
based on the RFI present and the characteristics of the source signal. We show
by flagging a small percentage of the spectrum we can substantially improve the
quality of transit observations.
