Previous studies [Tiemann et al., J. Acoust. Soc. Am. 120, 2355-2365 (2006)] have reported the localization of marine mammals in 3-D from their clicks using multipath arrivals. Bathymetric variations were advantageously used to predict multipath arrival times with a raytracer. These arrivals are directly discernible from the time series for impulsive sources, such as whale clicks, but extension of the method to continuous broadband sources presents additional complications. By pulse compressing noise emitted from a small boat using two hydrophones, the hyperbolic direct-arrival ambiguity can be refined in both range and bearing. Acoustic-derived results are validated with target GPS measurements.
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http://dx.doi.org/10.1121/1.4809771 | DOI Listing |
Sensors (Basel)
December 2024
School of Physics, Xidian University, Xi'an 710071, China.
Localization accuracy in non-line-of-sight (NLOS) scenarios is often hindered by the complex nature of multipath propagation. Traditional approaches typically focus on NLOS node identification and error mitigation techniques. However, the intricacies of NLOS localization are intrinsically tied to propagation challenges.
View Article and Find Full Text PDFJ Acoust Soc Am
December 2024
Naval Physical and Oceanographic Laboratory, Defence Research and Development Organisation, Thrikkakara P. O., Kochi, Kerala 682021, India.
An acoustic propagation experiment was conducted in the western continental shelf of India (off Kollam, Kerala) in water depth of ∼71 m with seafloor consisting of hard sandy sediments. The multipath arrival times are obtained from peaks in acoustic impulse response measurements made on a single hydrophone for two source-receiver ranges of 245 m and 320 m. The arrival times are used for inverting the water column sound speed profile (SSP) utilizing the empirical orthogonal functions (EOFs), which can completely describe large datasets.
View Article and Find Full Text PDFSensors (Basel)
September 2024
School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China.
Recently, indoor positioning has been one of the hot topics in the field of navigation and positioning. Among different solutions on indoor positioning, positioning with acoustic signals has its promise due to its relatively high accuracy in the line of sight scenarios, low cost, and ease of being implemented in smartphones. In this work, a novel acoustic positioning method, called RATBILS, is proposed, in which encoded chirp acoustic signals are modulated and transmitted by different acoustic base stations.
View Article and Find Full Text PDFSensors (Basel)
September 2024
The Wireless Lab, EMT Centre, Institut National de la Recherche Scientifique (INRS), Montreal, QC H5A 1K6, Canada.
In this paper, we propose a new data-aided (DA) joint angle and delay (JADE) maximum likelihood (ML) estimator. The latter consists of a substantially modified and, hence, significantly improved gray wolf optimization (GWO) technique by fully integrating and embedding within it the powerful importance sampling (IS) concept. This new approach, referred to hereafter as GWOEIS (for "GWO embedding IS"), guarantees global optimality, and offers higher resolution capabilities over orthogonal frequency division multiplex (OFDM) (i.
View Article and Find Full Text PDFSci Rep
July 2024
College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518000, China.
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