  In detecting shallow buried underground objects, reflected power from ground,
i.e. ground surface clutter makes the task extremely difficult. In order to
remove ground clutter, conventional methods in the literature are not as much
effective as we need for objects buried detection in shallow depths. In this
paper, a robust method, based on Time gating and wiener filtering, is proposed,
which is very precise and effective in Ultra wideband (UWB) imaging. The
problem with time gating method solely is that the timing window length for
unknown target depths cannot be determined beforehand with sufficient accuracy.
Imprecise window length selection removes parts of target signals along with
the clutter and increases missed detection probability. This paper proposes an
algorithm to circumvent this problem by first using a wiener filter for
cancellation of ground clutter to a reasonable extent and pre detection of
target positions by average similarity function (ASF). The time gating method
is then used in the second step using the information provided from the first
step for window length selection. The combination of the two steps provides
better detection of shallow buried objects with less missed detection of
targets.
