Multitarget Initiation, Tracking and
Termination Using Bayesian Monte
Carlo Methods
WILLIAM NG
*
,JACK LI,SIMON GODSILL AND SZE KIM PANG
Department of Engineering, University of Cambridge, CB2 IPZ Cambridge, UK
*Corresponding author: kfn20@acm.ac.uk
In this paper, we present an online approach for joint initiation/termination and tracking for
multiple targets with multiple sensors using sequential Monte Carlo (SMC) methods. There are
several main contributions in the paper. The first contribution is the extension of the deterministic
initiation and termination method proposed by the authors’ previous publications to a full SMC
context in which track initiation/termination are executed with sampling methods. In effect, the
dimensions of the particles are variable. In addition, we also integrate a Markov random field
(MRF) motion model with the framework to enable efficient and accurate tracking for interacting
targets and to avoid potential track coalescence problems. With the employment of multiple
sensors, a centralized tracking strategy is adopted, where the observations from all active
sensors are fused together for target initiation/termination and tracking and a set of global
tracks is maintained. Intra- and inter-sensor clusters are constructed, comprised of closely
spaced observations either in time for single sensors or from distinct sensors at a single time,
that can increase the reliability when proposing new tracks for initiation. Computer simulations
demonstrate that the proposed approach is robust in joint initiation/termination and tracking of
multiple manoeuvring targets even when the environment is hostile with high-clutter rates and
low target detection probabilities. The integration of the MRF framework into the proposed
methods improves robustness in handling close target interactions when the observation noise
is high.
Keywords: multitarget tracking; multiple sensors; data and track fusion; Markov random field; particle
filter; sequential Monte Carlo; clustering algorithm
Received 22 May 2007; revised 22 May 2007
1. INTRODUCTION
Multitarget tracking (MTT) [1–3] is an important element of
surveillance and monitoring systems that require the determi-
nation of the number as well as the dynamics of targets. Appli-
cations include radar and sonar-based tracking of objects for
navigation and air traffic control. In practice, a tracking
system, which relies on a single sensor for target detection and
tracking, is vulnerable to errors and noise problems. The short-
comings single-sensor systems suffer can be mitigated to a large
extent when additional sensors are deployed. For instance, when
multiple sensors are distributed at widely separated locations,
the system is capable of providing a clearer and more reliable
view of activities within the surveillance region than a
single-sensor system. As a result, more accurate and reliable
target detection and tracking can be achieved from multiple-
sensor (multisensor) systems. More detailed discussions on the
features and the types of multiplesensor tracking systems can
be found in [4–6].
In reality, multisensor tracking applications face some
significant challenges. First, the number of targets is unknown
and must automatically be determined for successful operation.
Second, the state-space models are often nonlinear and non-
Gaussian so that no closed-form analytic solution can be
obtained. As a result, methods relying on the linear and Gaussian
assumptions are susceptible to failure. Third, a real-world target
often moves in straight lines with constant velocity and
occasionally manoeuvres abruptly during its motion. A single
dynamical model for modelling the target motions is not typi-
cally enough to represent this behaviour. To address this issue,
interactive multiple models (IMMs) are proposed [7– 10],
where each model, representing a different type of target
THE COMPUTER J OURNAL, Vol. 50 No. 6, 2007
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doi:10.1093/comjnl/bxm070