scholarly journals Multisensor towed array detection system for UXO detection

2001 ◽  
Vol 39 (6) ◽  
pp. 1139-1145 ◽  
Author(s):  
H.H. Nelson ◽  
J.R. McDonald
Keyword(s):  
Detection System ◽  
Array Detection ◽  
Towed Array

scholarly journals Identification and Removal of Non-acoustic Noise in Towed Array Sonar Using F-Κ Transform for Enhanced Torpedo Detection

2020 ◽  
Vol 14 ◽  
Keyword(s):  
Vibration Isolation ◽  
Acoustic Noise ◽  
Detection System ◽  
Mechanical Vibration ◽  
Low Frequency ◽  
Acoustic Energy ◽  
Noise Sources ◽  
Towed Array ◽  
Spatio Temporal ◽  
Towed Arrays

Low frequency passive towed array sonar is an essential component in a torpedo detection system for surface ships. Compact towed arrays are used for torpedo detection and they will be towed at higher towing speeds compared to conventional towed array sonars used for surveillance. Presence of non-acoustic noise in towed array sensors at higher towing speeds degrades torpedo detection capability at lower frequencies. High wavenumber mechanical vibrations are induced in the array by vortex shedding associated with hydrodynamic flow over the array body and cable scope. These vibrations are known to couple into the hydrophone array as nonacoustic noise sources and can impair acoustic detection performance, particularly in the forward end fire direction. Lengthy mechanical vibration isolation modules can isolate vibration induced noise in towed arrays, but this is not recommended in a towed array which is towed at high speeds as it will increase the drag and system complexity. An algorithm for decomposing acoustic and non-acoustic components of signals received at sensor level using well known frequency-wavenumber transform (F-K transform) is presented here. Frequency-wavenumber diagrams can be used for differentiating between acoustic and non-acoustic signals. An area of V shape is identified within the F-K spectrum where acoustic energy is confined. Energy outside this V will highlight non-acoustic energy. Enhanced simultaneous spatio-temporal and spatio-amplitude detection is possible with this algorithm. Performance of this algorithm is validated through simulation and experimental data.

Novel design for suspension array detection system

2005 ◽  
Author(s):  
Guoxiong Xu ◽  
Yan Shi ◽  
Xuxiang Ni ◽  
Zukang Lu
Keyword(s):  
Detection System ◽  
Suspension Array ◽  
Array Detection ◽  
Novel Design

Research on a New Detection Technique of FBG Using OTDR

2011 ◽  
Vol 317-319 ◽  
pp. 2346-2350
Author(s):  
Xiu Mei Jin ◽  
Yu Mei Lv ◽  
Li Feng Du
Keyword(s):  
Time Domain ◽  
Detection System ◽  
Time Domain Reflectometry ◽  
Resonance Peak ◽  
Optical Time Domain Reflectometry ◽  
Array Detection ◽  
A New Technique ◽  
Optical Time ◽  
Reflected Power ◽  
Time Division

A new technique of using Optical Time Domain Reflectometry (OTDR) to detect the reflected power of FBG sensing array was researched systematically. The theoretical model between the reflected power detected by OTDR and the reflected wavelength of FBG was established by analyzing, and consequently the selection rule of FBG wavelength in OTDR detection system was proposed. Moreover, experiments about multi-combination of FBGs with high reflectivity were carried out. The cause of dummy peak and resonance peak in OTDR test curves were analyzed, and meanwhile the selection basis of FBG reflectivity was also given. Based on time division multiplexing theory, detecting low-reflectivity FBG by OTDR can increase the FBG multiplexing number greatly, which has wide prospect to be applied in FBG array detection.

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