The Multiple Airborne Sensor Targeting and Evaluation Rig (MASTER) is a high fidelity simulation environment in
which data fusion, tracking and sensor management algorithms developed within QinetiQ Ltd. can be demonstrated and
evaluated. In this paper we report an observer trajectory planning tool that adds considerable functionality to MASTER.
This planning tool can coordinate multiple sensor platforms in tracking highly manoeuvring targets. It does this by
applying instantaneous thrusts to each platform, the magnitude of which is chosen to gain maximum observability of
the target. We use an efficient search technique to determine the thrust that should be applied to each platform at each
time step, and the planning horizon can either be one-step (greedy) or two-step. The measure of performance used in
evaluating each potential sensor manoeuvre (thrust) is the posterior Cramer-Rao lower bound (PCRLB), which gives the
best possible (lowest mean square error) tracking performance. We exploit a recent novel approach to approximating the
PCRLB for manoeuvring target tracking (the "best-fitting Gaussian" (BFG) approach: Hernandez et al., 2005). A closed-form
expression gives the BFG approximation at each sampling time. Hence, the PCRLB can be approximated with a very
low computational overhead. As a result, the planning tool can be implemented as an aid to decision-making in real-time,
even in this time-critical airborne domain. The functionality of MASTER enables one to access the performance of the
planning tool in a range of sensor-target scenarios, enabling one to determine the minimal sensor requirement in order to
satisfy mission requirements.