It has been shown previously that the Histogram Probabilistic Multi-Hypothesis Tracking (HPMHT) algorithm enables tracking of targets distributed across several sensor cells. Two related aspects of the H-PMHT algorithm are discussed in this paper, namely the estimation of target spread, and the use of the negative multinomial distribution to compensate for unobserved sensor cells. The examples ...

The generation of three-dimensional ( 3 0 ) images and map building are essential components in the development of an autonomous underwater system. Although the direct generution of 3 -0 images is more efficient than the recovery of 3 -0 data from 2-D idormation, at present for underwater applications where sonar is the main form of remote sensing, the generation of 3 -0 images can only be achi...

In this chapter, we present two applications in information fusion in order to evaluate the generalized proportional conflict redistribution rule presented in the chapter [5]. Most of the time the combination rules are evaluated only on simple examples. We study here different combination rules and compare them in terms of decision on real data. Indeed, in real applications, we need a reliable ...

A novel, flexible, three-dimensional multisensor sonar system is described to localize the center of a generalized spherical target and estimate its radius of curvature. Point, line, and planar targets are included as limiting cases which are important for the characterization of a mobile robot’s environment. Sensitivity analysis of the curvature estimate with respect to measurement errors and ...

Our long term goal is to develop accurate models for high-frequency acoustic penetration into, propagation within, and scattering from shallow water ocean sediments. This work should specifically improve the Navy’s ability to detect buried mines and, in general, improve sonar performance in shallow water. Additional objectives of the NRL program are to understand and model the complex interacti...

The echo statistics associated with a randomly oriented prolate spheroid randomly located in the sonar beam are modeled. The cases of a smooth and rough spheroid, both in the water column (i.e., case in which boundaries are not involved), and on a boundary are investigated. The modeling begins with the analytical physics-based expression for the scattering amplitude of a smooth prolate spheroid...

Inherent in passive sonar are several challenges that any effective system implementation must address. One of these challenges is how to best treat multipath arrivals. In some cases these can be a hindrance while in this research they are exploited. In certain environments, different arrivals (multipath and direct) retain significant coherence with respect to each other. This fact has been not...

The long term goals of this project are: i) to predict and understand the characteristics of active and passive time reversing array (TRA) performance in shallow ocean waters, ii) to deduce the effectiveness of using a TRA for underwater communication and for surveillance of the acoustic characteristics of known or unknown environments, and iii) to determine how to exploit the generic propagati...

Abstract. Doppler sonar observations of surface velocity are analysed to extract an rms velocity scale related to flow patterns persisting for at least a minute, and having advection velocities within an adjustable "window" of the mean advection rate. The resulting velocity scale is related to the wind and waves over the course of the twenty days available from the SWAPP data set. The correlati...