  Searching for concealed threats within a surveillance region is an important
role for military sensors. One prominent case is the search for a submarine by
a helicopter deploying a dipping sonar in anti-submarine warfare. Another is
the utilisation of an uncrewed aerial vehicle for remote detection of land
mines. These platforms will deploy an appropriate sensor to search within a
given region for a potential threat. The sensors employed may not provide
continuous surveillance, but may have active periods where the inherent sensor
is scanning for threats. The reasons for disjoint activation periods may be
both functional as well as tactical. Therefore, given a specified search
pattern under which the surveillance platform operates, the question of the
number of sensor scans required becomes relevant for search mission
pre-planning. Hence it is not only important to develop a modelling framework
to assess performance but it is of relevance to consider whether a minimum
number of sensor scans can be determined to guarantee a desired level of
performance. Consequently this paper introduces a framework for this and
illustrates how it can be utilised in practice.
