Joint Tracking of Source and Environment Using Improved Particle Filtering in Shallow Water

Abstract

Shallow water is a complex sound propagation medium, which is affected by the varying spatial–temporal ocean environment. Taking this complexity into account, the classical processing techniques of source localization and environmental inversion may be improved. In this work, a joint tracking approach for the moving source and environmental parameters of the range-dependent and time-evolving environment in shallow water is presented. The tracking scheme treats both the source parameters (e.g., source depth, range, and speed) and the environmental parameters (e.g., water column sound speed profile (SSP) and sediment parameters) at the source location as unknown variables that evolve as the source moves. To counter sample impoverishment and robustly characterize the evolution of the parameters, an improved particle filter (PF), which is an extension of the standard PF, is proposed. Two examples with simulated data in a slowly changing environment and experimental data collected during the ASIAEX experiment are utilized to demonstrate the effectiveness of the joint approach. The results show that we were able to track the source and environmental parameters simultaneously, and the uncertainties were evaluated in the form of time-evolving posterior probability densities (PPDs). The performance comparison confirms that the improved PF is superior to the standard PF, as it can reduce the parameter uncertainties. The tracking capabilities of the improved PF were verified with high accuracy in real-time source localization and well-estimated rapidly varying parameters. Moreover, the influence of different particle numbers on the improved PF tracking performance is also illustrated.

Mesh Optimization for the Acoustic Parabolic Equation

“…[31]. These include remote sensing of the movement of ships and marine life [32], as well as determination of their characteristics [33]. Computer modeling is used to characterize sea currents and the seabed [34], and for estimating the global noise level from shipping and its impact on the world's oceans [35,36].…”

Modeling Techniques for Underwater Acoustic Scattering and Propagation (Including 3D Effects)

“…Papers of the second type are related to applications of underwater acoustics where the models of sound propagation play a significant role [8][9][10][11]. These include geoacoustic inversion [9], source-bearing estimation [8], a technique that allows one to estimate both the source position and the media properties [11], and the problem of estimating the acoustic noise levels over some water areas neighbouring the source [10].…”

“…Papers of the second type are related to applications of underwater acoustics where the models of sound propagation play a significant role [8][9][10][11]. These include geoacoustic inversion [9], source-bearing estimation [8], a technique that allows one to estimate both the source position and the media properties [11], and the problem of estimating the acoustic noise levels over some water areas neighbouring the source [10]. For example, the novel geoacoustic inversion technique from [9] requires the precise calculation of ray paths (which is performed using the BELLHOP code) that are necessary to estimate travel times of head waves.…”