  This paper presents an analysis on sensor management using a cost function
based on a multi-target metric, in particular, the optimal
subpattern-assignment (OSPA) metric, the unnormalised OSPA (UOSPA) metric and
the generalised OSPA (GOSPA) metric (\alpha=2). We consider the problem of
managing an array of sensors, where each sensor is able to observe a region of
the surveillance area, not covered by other sensors, with a given sensing cost.
We look at the case in which there are far-away, independent potential targets,
at maximum one per sensor region. In this set-up, the optimal action using
GOSPA is taken for each sensor independently, as we may expect. On the
contrary, as a consequence of the spooky effect at a distance in optimal
OSPA/UOSPA estimation, the optimal actions for different sensors using OSPA and
UOSPA are entangled.
