Article
Engineering, Marine
Jonghoek Kim
Summary: This article discusses the localization of a noncooperative underwater transmitter using multiple receivers to measure the frequency difference of arrival (FDOA) and the time difference of arrival (TDOA) of the transmitter's sound. It focuses on the case where the emission frequency of the transmitter is unknown and changes over time. The article proposes a hybrid TDOA-FDOA localization approach assuming knowledge of the transmitter's maximum speed. MATLAB simulations confirm the effectiveness of the proposed approach and demonstrate its superiority over incorrect frequency estimation.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Engineering, Multidisciplinary
Yingying Li, Hang Jiang, Lianjie Yu, Jianfeng Li
Summary: In order to improve the accuracy of estimation, a novel time delay estimation (TDE) method based on closed-form offset compensation is proposed. The method uses the GCC-PHAT method to obtain the initial TDE, establishes a signal model using normalized cross spectrum, and extracts the noise subspace using eigenvalue decomposition (EVD) of covariance matrix. By utilizing the orthogonal relation between the steering vector and the noise subspace, the first-order Taylor expansion is applied to the reconstructed steering vector. Offsets are then compensated using simple least squares (LS). Compared to other methods, the proposed method reduces computational complexity and achieves better estimation performance, as verified by experiments on both simulation and real-world data.
CMES-COMPUTER MODELING IN ENGINEERING & SCIENCES
(2023)
Article
Engineering, Electrical & Electronic
Wenqi Tang, Wenzhong Qu, Ling You, Tianyun Li, Jirong Xin, Songqiao Yang
Summary: The geomagnetic field splits an electromagnetic wave into two characteristic waves, the ordinary (O) and extraordinary (X) waves. A model is developed for the oblique propagation of these waves to estimate the direction of arrival and elliptically polarized parameters. The O and X waveforms are separated based on polarization differences, and the performance is validated through simulation and experiments.
IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
(2023)
Article
Acoustics
Jiajia Jiang, Chunyue Li, Xianquan Wang, Zhongbo Sun, Xiao Fu, Fajie Duan
Summary: A bio-inspired covert underwater acoustic communication method based on combined encoding of diverse time-frequency characteristics of sperm whale clicks is proposed, which improves communication rate and camouflage ability. The communication sequences constructed include a large number of different modulated clicks, conforming to the characteristics of true click pulse trains. This method improves camouflage ability by inserting true sperm whale click pulses as camouflage pulses.
Article
Audiology & Speech-Language Pathology
Zeeshan Haqqee, Roberto Valdizon-Rodriguez, Paul A. Faure
Summary: The study investigates the response properties of single neurons in the inferior colliculus of big brown bats to onset ITDs in high frequency pure tones. It found that neurons show sensitivity to onset ITD cues, with an average change of 36% of its maximal response within a behaviorally relevant range of ITDs. Additionally, there is a consistent average time-intensity trading ratio of 30 mu s/dB in the sensitivity of the ITD response function to changing ILDs, indicating the potential use of onset ITD cues for azimuthal sound localization in echolocating bats.
Article
Engineering, Electrical & Electronic
Stefano Bottigliero, Daniele Milanesio, Maurice Saccani, Riccardo Maggiora
Summary: This article introduces a new real-time locating system (RTLS) that utilizes ultrawideband impulse radio (IR-UWB) technology to evaluate the position of tags with an optimum localization accuracy of 10 cm by computing the time difference of arrival (TDOA) of UWB pulse sequences.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2021)
Article
Engineering, Electrical & Electronic
Jinqi Liu, Ge Guo
Summary: This paper introduces new variants of the pseudolinear Kalman filter (PLKF) for target tracking in 2D-plane, as well as a closed-form PLKF and a new variant of instrumental variable-based Kalman filter (IVKF). Simulation results demonstrate that the proposed estimators significantly outperform traditional estimators.
Article
Physics, Multidisciplinary
Roderich Tumulka
Summary: This study investigates the computation of the probability distribution of the time and place at which a quantum particle gets detected by a detector surface in the non-relativistic regime. The distribution is defined by solving the Schrodinger equation for a quantum system consisting of the particle of interest, the detector, a clock, and a device that records the time and place of detection, and then making a quantum measurement of the record at a very late time. The study proposes a rule based on a one-dimensional Schrodinger equation with a specific (absorbing) boundary condition at the ideal detecting surface and describes how it emerges as a limit of a soft detector represented by an imaginary potential.
Article
Computer Science, Information Systems
Shuai Shao, Aijun Liu, Xiuhong Wang, Changjun Yu
Summary: This article introduces a novel method for estimating the direction of arrival (DOA) of weak nonstationary polarization signals by utilizing spatial polarimetric time-frequency distributions (SPTFDs) in the presence of strong interference signals and noise. The combination of SPTFDs and polarization information improves the accuracy of DOA estimation.
Article
Engineering, Aerospace
Qin Li, Jian Lan, Le Zhang, Badong Chen, Kaijian Zhu
Summary: This article proposes an estimation method for nonlinear least squares problems and provides theoretical analysis to support its effectiveness. The method includes a unified linearization approach and an augmented nonlinear least squares estimator, which are applied to source localization.
IEEE TRANSACTIONS ON AEROSPACE AND ELECTRONIC SYSTEMS
(2022)
Article
Engineering, Electrical & Electronic
Wenjin Wang, Tingting Chen, Rui Ding, Gonzalo Seco-Granados, Li You, Xiqi Gao
Summary: The paper investigates location-based timing advance (TA) estimation for 5G integrated LEO satellite communication systems, using TDOA and FDOA measurements to calculate the TA value and ensure uplink frame alignment.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2021)
Article
Chemistry, Multidisciplinary
Nabeel Ali Khan, Sadiq Ali, Kwonhue Choi
Summary: An efficient direction of arrival estimation method is proposed, accurately estimating the instantaneous frequency of signals to separate sources and estimate their direction of arrivals. Experimental results show better performance in computational requirements and localization accuracy compared to existing methods.
APPLIED SCIENCES-BASEL
(2021)
Article
Engineering, Electrical & Electronic
J. Selva
Summary: This paper presents a method for estimating the signal subspace at all frequencies in a given band. The method utilizes the usual set of frequency-bin sample covariance matrices in wideband subspace estimation. It models the signal subspace using a projection matrix function approximated by a polynomial. The method provides improvements in representation size and quality of wideband direction-of-arrival estimators.
Article
Computer Science, Information Systems
Xinran Ba, Chen Lin, Yincheng Zhong, Guanjiao Ren, Zhengpeng Wang, Yi Wang
Summary: A novel compact auto-tracking antenna system was developed for high reliability of practical applications. The system achieved high tracking reliability with a 90% success rate using a correlation matching algorithm based on the phase difference of arrival.
Article
Chemistry, Analytical
Donghyeon Kim, Gihoon Byun, Jeasoo Kim
Summary: Frequency-wavenumber (f-k) analysis is used to estimate the direction of arrival (DOA) of broadband signals received on a vertical array. When the array configuration is sparse, spatial sampling leads to aliasing error and multiple striation patterns can appear in the f-k domain. This paper extends the f-k analysis to a sparse receiver array and introduces the concept of frequency differencewavenumber (delta f-k) analysis for DOA estimation. Experimental results demonstrate the robustness of the proposed delta f-k analysis in estimating the DOA of cracking sounds generated by snapping shrimps.
Article
Environmental Sciences
Laura Palmer, Douglas Gillespie, Jamie D. J. MacAulay, Carol E. Sparling, Debbie J. F. Russell, Gordon D. Hastie
Summary: The study conducted in Scotland showed that harbour porpoises exhibited significant avoidance of a tidal turbine when it was operating, with avoidance increasing with flow speed. The temporal variability in encounter rate highlighted the need for long-term baseline monitoring to understand collision risk more comprehensively. It is important to assess the generality of avoidance rates presented in this study for different sites, turbine types, array sizes, and cetacean species as the tidal industry expands, to balance the benefits of avoidance responses with potential chronic effects of displacement from important habitats.
AQUATIC CONSERVATION-MARINE AND FRESHWATER ECOSYSTEMS
(2021)
Article
Biology
Ilias Foskolos, Michael Bjerre Pedersen, Kristian Beedholm, Astrid Sormark Uebel, Jamie Macaulay, Laura Stidsholt, Signe Brinklov, Peter Teglberg Madsen
Summary: This study found that bats are able to maintain adequate echo-to-noise ratios for prey hunting by increasing call amplitude, even when they cannot avoid masking spectrally, spatially or temporally.
JOURNAL OF EXPERIMENTAL BIOLOGY
(2022)
Article
Ecology
Jamie Macaulay, Al Kingston, Alex Coram, Michael Oswald, Rene Swift, Doug Gillespie, Simon Northridge
Summary: A passive acoustic monitoring system was developed to track the behavior of harbour porpoises around fishing nets. By localizing their acoustic clicks, highly detailed 3D movement data can be obtained. The study revealed various behaviors of harbour porpoises in proximity to nets, including active foraging.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Correction
Biology
Ilias Foskolos, Michael Bjerre Pedersen, Kristian Beedholm, Astrid Saermark Uebel, Jamie Macaulay, Laura Stidsholt, Signe Brinklov, Peter Teglberg Madsen
JOURNAL OF EXPERIMENTAL BIOLOGY
(2022)
Article
Environmental Sciences
Douglas Gillespie, Michael Oswald, Gordon Hastie, Carol Sparling
Summary: This article reports on the design and performance of a seabed mounted sensor platform for monitoring the fine scale movements of cetaceans and pinnipeds around operational tidal turbines. The system uses high-frequency multibeam active sonars for tracking animals in the horizontal plane and offsetting the vertical angle of the sonars to resolve a vertical component. It also utilizes hydrophones for measuring angles to cetacean echolocation clicks. The system proved highly reliable during field tests and will be deployed close to an operational turbine.
FRONTIERS IN MARINE SCIENCE
(2022)
Article
Ecology
Thomas Webber, Douglas Gillespie, Timothy Lewis, Jonathan Gordon, Tararak Ruchirabha, Kirsten F. Thompson
Summary: Passive acoustic surveys are popular for surveying marine species, but data analysis is time-consuming and expensive. Researchers have developed a semi-automatic workflow to reduce the time and cost for analysts.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Article
Ecology
Kaitlin J. Palmer, Sam Tabbutt, Douglas Gillespie, Jesse Turner, Paul King, Dominic Tollit, Jessica Thompson, Jason Wood
Summary: There is significant support for offshore wind development in US waters, but some planned sites overlap with critical habitat for endangered right whales. In order to manage the interactions between marine mammals and human activities, exclusion zones and passive acoustic monitoring are important tools. Researchers have developed a three-hydrophone system that provides real-time information about the location of marine mammals with respect to exclusion zones. Field trials showed that the system can effectively monitor exclusion zones and improve false alarm rates.
METHODS IN ECOLOGY AND EVOLUTION
(2022)
Article
Acoustics
Peter C. Conant, Pu Li, Xiaobai Liu, Holger Klinck, Erica Fleishman, Douglas Gillespie, Eva-Marie Nosal, Marie A. Roch
Summary: This work presents an open-source Matlab software package for extracting tonal signals from large acoustic data sets, and incorporates a whistle extraction algorithm into an established software package for cetacean tonal calls. The algorithm performs well on challenging species subsets and shows good generalization to new data.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Acoustics
E. G. Longden, D. Gillespie, D. A. Mann, K. A. McHugh, A. M. Rycyk, R. S. Wells, P. L. Tyack
Summary: This study analyzed the changes in vessel activity and soundscape during the COVID-19 pandemic in Sarasota Bay and its impact on bottlenose dolphins. The results showed an increase in vessel activity and a decrease in dolphin whistle detection during the pandemic, indicating that the effects of the pandemic on wildlife are not consistent across different regions.
JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA
(2022)
Article
Biology
Erica Fleishman, Danielle Cholewiak, Douglas Gillespie, Tyler Helble, Holger Klinck, Eva-Marie Nosal, Marie A. Roch
Summary: Monitoring based on sound recordings can provide valuable data for estimating ecological metrics at both individual and community levels in marine ecosystems. However, the reliability and feasibility of passive acoustic monitoring vary depending on various factors, and collaborations between researchers from different fields are crucial to improve the accuracy and applicability of these methods.
BIOLOGICAL REVIEWS
(2023)
Article
Ecology
Signe M. M. Brinklov, Jamie Macaulay, Christian Bergler, Jakob Tougaard, Kristian Beedholm, Morten Elmeros, Peter Teglberg Madsen
Summary: The affordability, storage, and power capacity of compact modern recording hardware have made passive acoustic monitoring (PAM) a non-invasive, cost-effective tool for research and ecological management. However, there is a need for standardized, user-friendly, and open access automated detection and classification workflows for bats.
METHODS IN ECOLOGY AND EVOLUTION
(2023)
Article
Engineering, Marine
Douglas Gillespie, Gordon Hastie, Jessica Montabaranom, Emma Longden, Katie Rapson, Anhelina Holoborodko, Carol Sparling
Summary: Understanding the behavior of marine animals around tidal turbines is crucial for assessing their impact on individuals and populations. A study using multibeam sonar data near an operational turbine in Scotland identified tracks of marine mammals, fish, and diving birds. The data is being analyzed to study species reactions to turbine rotors and improve automated detection and classification algorithms.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Biology
I. M. Graham, D. Gillespie, K. C. Gkikopoulou, G. D. Hastie, P. M. Thompson
Summary: Mitigation measures to disperse marine mammals prior to pile-driving, such as acoustic deterrent devices and piling soft starts, have uncertain efficacy. However, through the use of portable hydrophone clusters, it has been demonstrated that harbour porpoises respond positively to these measures by swimming away from the sound sources.
Article
Multidisciplinary Sciences
Shyam Madhusudhana, Yu Shiu, Holger Klinck, Erica Fleishman, Xiaobai Liu, Eva-Marie Nosal, Tyler Helble, Danielle Cholewiak, Douglas Gillespie, Ana Sirovic, Marie A. Roch
Summary: This study explores the use of the temporal context in long-form songs to improve automatic recognition performance. By combining convolutional neural network and long short-term memory network models, the system can accurately detect sequences of song notes, offering a valuable pathway for improving wildlife recordings recognition and transcription.
JOURNAL OF THE ROYAL SOCIETY INTERFACE
(2021)
