1
Poisson multi-Bernoulli mixture filter with general
target-generated measurements and arbitrary clutter
Ángel F. García-Fernández, Yuxuan Xia, Lennart Svensson
Abstract—This paper shows that the Poisson multi-Bernoulli
mixture (PMBM) density is a multi-target conjugate prior for
general target-generated measurement distributions and arbi-
trary clutter distributions. That is, for this multi-target mea-
surement model and the standard multi-target dynamic model
with Poisson birth model, the predicted and filtering densities are
PMBMs. We derive the corresponding PMBM filtering recursion.
Based on this result, we implement a PMBM filter for point-
target measurement models and negative binomial clutter density
in which data association hypotheses with high weights are
chosen via Gibbs sampling. We also implement an extended
target PMBM filter with clutter that is the union of Poisson-
distributed clutter and a finite number of independent clutter
sources. Simulation results show the benefits of the proposed
filters to deal with non-standard clutter.
Index Terms—Multi-target filtering, Poisson multi-Bernoulli
mixtures, Gibbs sampling, arbitrary clutter.
I. INTRODUCTION
Multi-target filtering consists of estimating the current states
of an unknown and variable number of targets based on noisy
sensor measurements up to the current time step. It is a key
component of numerous applications, for example, defense [1],
automotive systems [2] and air traffic control [3]. Multi-target
filtering is usually addressed using probabilistic modelling,
with the main approaches being multiple hypothesis tracking
[4], joint probabilistic data association [5] and random finite
sets [6].
In detection-based multi-target filtering, sensors collect
scans of data that may contain target-generated measurements
as well as clutter, which refers to undesired detections. For
example, in radar, clutter can be caused by reflections from the
environment, such as terrain, sea and rain, or other undesired
objects [7], [8]. Multi-target filters applied to real data must
then account for these clutter measurements for suitable per-
formance, for instance, sea clutter and land clutter in radar data
[9], false detections in image data [10], [11], false detections
in audio visual data [12], and underwater clutter in active sonar
data [13], [14].
In the standard detection model, clutter is modelled as
a Poisson point process (PPP) [6]. The PPP is motivated
by the fact that, for sufficiently high sensor resolution and
independent clutter reflections in each sensor cell, the detection
A. F. García-Fernández is with the Department of Electrical Engineer-
ing and Electronics, University of Liverpool, Liverpool L69 3GJ, United
Kingdom (angel.garcia-fernandez@liverpool.ac.uk). He is also with the
ARIES Research Centre, Universidad Antonio de Nebrija, Madrid, Spain.
Y. Xia and L. Svensson are with the Department of Electrical Engineering,
Chalmers University of Technology, SE-412 96 Gothenburg, Sweden (first-
name.lastname@chalmers.se).
process can be accurately approximated as a PPP [15]. The
PPP is also convenient mathematically and it can be char-
acterised by its intensity function on the single-measurement
space.
For the point-target measurement model, PPP clutter and
the standard multi-target dynamic model with PPP birth, the
posterior is a Poisson multi-Bernoulli mixture (PMBM) [16],
[17]. The PMBM consists of the union of a PPP, representing
undetected targets, and an independent multi-Bernoulli mix-
ture (MBM) representing targets that have been detected at
some point and their data association hypotheses. The posterior
density is also a PMBM for the extended target model [18] and
for a general target-generated measurement model [19], both
with PPP clutter and the standard dynamic model. Extended
target modelling is required when, due to the sensor resolution
and the target extent, a target may generate more than one de-
tection at each time step [20]. This makes the data association
problem considerably more challenging than for point targets.
The general target generated-measurement model includes the
point and extended target cases as particular cases, and can for
example be used when there can be simultaneous point and
extended targets in a scenario [19].
If the birth model is multi-Bernoulli instead of PPP, the
posterior density in the above cases is an MBM, which is
obtained by setting the Poisson intensity of the PMBM filter
to zero and by adding the Bernoulli components of the birth
process in the prediction step. The MBM filter can also be
written in terms of Bernoulli components with deterministic
target existence, which results in the MBM01 filter [17, Sec.
IV]. It is also possible to add unique labels to the target
states in the MBM and MBM01 filters. The (labelled) MBM01
filtering recursions are analogous to the δ-generalised labelled
multi-Bernoulli (δ-GLMB) filtering recursions [21], [22].
All the above recursions to compute the posterior assume
PPP clutter, but other clutter distributions are also important
in various contexts, for instance, to model bursts of radar sea
clutter [23]. For general target-generated measurements and
arbitrary clutter density, the Bernoulli filter was proposed in
[24], and the probabilistic hypothesis density (PHD) filter,
which provides a PPP approximation to the posterior, was
derived in [25]. The corresponding PHD filter update depends
on the set derivative of the logarithm of the probability
generating functional (PGFL) of the clutter process. A version
of this PHD filter update, written in terms of densities, which
is more suitable for implementation than [25], is provided
in [26]. There are also other PHD filter variants with non-
PPP clutter for point targets, for example, a PHD filter with
negative binomial clutter [27], a second order PHD filter with
arXiv:2210.12983v2 [stat.AP] 24 May 2023