  One of the tasks of the Kepler Asteroseismic Science Operations Center
(KASOC) is to provide asteroseismic analyses on Kepler Objects of Interest
(KOIs). However, asteroseismic analysis of planetary host stars presents some
unique complications with respect to data preprocessing, compared to pure
asteroseismic targets. If not accounted for, the presence of planetary transits
in the photometric time series often greatly complicates or even hinders these
asteroseismic analyses. This drives the need for specialised methods of
preprocessing data to make them suitable for asteroseismic analysis. In this
paper we present the KASOC Filter, which is used to automatically prepare data
from the Kepler/K2 mission for asteroseismic analyses of solar-like planet host
stars. The methods are very effective at removing unwanted signals of both
instrumental and planetary origins and produce significantly cleaner
photometric time series than the original data. The methods are automated and
can therefore easily be applied to a large number of stars. The application of
the filter is not restricted to planetary hosts, but can be applied to any
solar-like or red giant stars observed by Kepler/K2.
