scholarly journals Source localization from time-differences of arrival using high-frequency communication signals

2011 ◽  
Author(s):  
Ehsan Zamanizadeh ◽  
Joao Gomes ◽  
Jose M. Bioucas-Dias
Keyword(s):  
Source Localization ◽  
High Frequency ◽  
Communication Signals

scholarly journals An Improved Algorithm for Noise Source Localization Based on Equivalent Source Method

2016 ◽  
Vol 2016 ◽  
pp. 1-13
Author(s):  
Zhongming Xu ◽  
Qinghua Wang ◽  
Yansong He ◽  
Zhifei Zhang ◽  
Shu Li ◽  
...  
Keyword(s):  
Source Localization ◽  
High Frequency ◽  
Noise Source ◽  
Near Field ◽  
Low Frequency ◽  
Equivalent Source ◽  
Source Method ◽  
Functional Equivalent ◽  
Acoustical Holography ◽  
Equivalent Source Method

Near-field acoustical holography (NAH) based on the equivalent source method (ESM) is an efficient method applied for noise source identification. Asl2-norm-based regularization cannot produce a satisfactory solution of the ill-conditioned problem in high frequency, the conventional ESM is restricted to relatively low frequency, and the resolution of conventional ESM in middle to high frequency remains a limitation open to investigation. This article presents an algorithm known as improved functional equivalent source method (IFESM), designed to enhance the resolution of conventional ESM. This method is developed in the framework of wideband acoustical holography (WBH) combining with functional beamforming (FB). Through numerical simulations, it is proved that the proposed method can localize noise with higher resolution compared with WBH and conventional ESM, and the ghosts on noise source map can be suppressed effectively. The validity and the feasibility of the proposed method are manifested by experiments including single-source and coherent-source localization.

High-frequency (8–16 kHz) model-based source localization

2004 ◽  
Vol 115 (6) ◽  
pp. 3021-3032 ◽  
Author(s):  
Paul Hursky ◽  
Michael B. Porter ◽  
Martin Siderius ◽  
Vincent K. McDonald
Keyword(s):  
Source Localization ◽  
High Frequency ◽  
Model Based

Regulation of Burst Dynamics Improves Differential Encoding of Stimulus Frequency by Spike Train Segregation

2007 ◽  
Vol 98 (2) ◽  
pp. 939-951 ◽  
Author(s):  
W. Hamish Mehaffey ◽  
Fernando R. Fernandez ◽  
Leonard Maler ◽  
Ray W. Turner
Keyword(s):  
Spike Train ◽  
High Frequency ◽  
Stimulus Frequency ◽  
Pyramidal Cells ◽  
Weakly Electric Fish ◽  
Inhibitory Input ◽  
Communication Signals ◽  
Frequency Components ◽  
Feedback Pathway ◽  
Intrinsic Burst

Distinguishing between different signals conveyed in a single sensory modality presents a significant problem for sensory processing. The weakly electric fish Apteronotus leptorhynchus use electrosensory information to encode both low-frequency signals associated with environmental and prey signals and high-frequency communication signals between conspecifics. We identify a mechanism whereby the GABAB component of a feedback pathway to the electrosensory lobe is recruited to regulate the intrinsic burst dynamics and coding properties of pyramidal cells for these behaviorally relevant input signals. Through recordings in an in vitro slice preparation and a reduced model of pyramidal cells, we show that recruitment of dendritic GABAB currents can shift the timing of a backpropagating spike and its influence on an intrinsic burst mechanism. This regulation of burst firing alters the coding properties of pyramidal cells by improving the correlation of burst and tonic spikes with respect to low- or high-frequency components of complex stimuli. GABAB modulation of spike backpropagation thus improves the segregation of burst and tonic spikes evoked by simulated sensory input, allowing pyramidal cells to parcel the spike train into coding streams for the low- and high-frequency components. As the feedback pathway is predicted to be activated in circumstances where environmental and communication stimuli coexist, these data reveal a novel means by which inhibitory input can regulate spike backpropagation to improve signal segregation.

scholarly journals Processing of simple and complex acoustic signals in a tonotopically organized ear

2014 ◽  
Vol 281 (1796) ◽  
pp. 20141872 ◽  
Author(s):  
Jennifer Hummel ◽  
Konstantin Wolf ◽  
Manfred Kössl ◽  
Manuela Nowotny
Keyword(s):  
High Frequency ◽  
Pure Tone ◽  
Neuronal Response ◽  
Mechanical Vibration ◽  
Laser Doppler Vibrometer ◽  
Low Frequency ◽  
Sensory Cells ◽  
Complex Signals ◽  
Communication Signals ◽  
Hearing Organ

Processing of complex signals in the hearing organ remains poorly understood. This paper aims to contribute to this topic by presenting investigations on the mechanical and neuronal response of the hearing organ of the tropical bushcricket species Mecopoda elongata to simple pure tone signals as well as to the conspecific song as a complex acoustic signal. The high-frequency hearing organ of bushcrickets, the crista acustica (CA), is tonotopically tuned to frequencies between about 4 and 70 kHz. Laser Doppler vibrometer measurements revealed a strong and dominant low-frequency-induced motion of the CA when stimulated with either pure tone or complex stimuli. Consequently, the high-frequency distal area of the CA is more strongly deflected by low-frequency-induced waves than by high-frequency-induced waves. This low-frequency dominance will have strong effects on the processing of complex signals. Therefore, we additionally studied the neuronal response of the CA to native and frequency-manipulated chirps. Again, we found a dominant influence of low-frequency components within the conspecific song, indicating that the mechanical vibration pattern highly determines the neuronal response of the sensory cells. Thus, we conclude that the encoding of communication signals is modulated by ear mechanics.

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