Experimental investigation of several passive sonar targets

Wallace, R. H.; Hillery, Herbert V.; Barnard, G. R.; Marks, Barry M.; McKinney, C. M.

doi:10.1121/1.380526

Cited by 20 publications

(6 citation statements)

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“…In operational conditions, both the topography, artifacts or objects present in the area can be a source of echoes making it difficult to discriminate these signatures from calibration targets. In 1975, (Wallace et al, 1975) presents the results of an experimental investigation of several passive sonar targets used for calibration, marking, and tracking. Although it is concluded that, of the targets studied, only the sphere can be used as calibration standards, we will favor a multi-triplane target design because of its higher target strength.…”

Section: Discussionmentioning

confidence: 99%

A Portable Opto-Acoustic Survey Solution for Mapping of Underwater Targets

Chemisky

Nocerino

Menna

et al. 2021

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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Abstract. During underwater investigations, whatever the mission objective and the type of vehicle, obstacles detection and avoidance are essential tasks. They can either represent a target of interest that is the object of the mission or, on the contrary, represent obstacles that can hinder or affect the navigation of the vehicle. The underwater optical cameras that are usually fitted to underwater vehicles only offer a narrow field of view. The absorption of electromagnetic waves in the first few meters and the diffusion of light by the particles limit the use of these sensors to only a few meters range. The use of acoustic sensors, such as the forward looking sonar (FLS), is then necessary to enlarge the volume in which a target can be detected during the progression of the vehicle. Traditionally, sonars featured mechanical rotating parts, but lately bidirectional forward looking sonar, which directly produces a 2D image of the area, are becoming more and more common. Although these sonars can operate at frequency higher than 1MHz, their spatial resolution remains much lower if compared to current optical sensors and can be insufficient to identify and characterize a target. The combination of these two sensors in an operational scenario is essential to take advantage of each technology. In this paper we describe a low cost, multi-sensor, underwater survey solution for the identification, tracking, and 3D mapping of targets. After a description of the architecture of the opto-acoustics data acquisition and processing platform, we will focus on the calibration of the rigid transformation between the two sensors.

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Section: Discussionmentioning

confidence: 99%

A Portable Opto-Acoustic Survey Solution for Mapping of Underwater Targets

Chemisky

Nocerino

Menna

et al. 2021

Int. Arch. Photogramm. Remote Sens. Spatial Inf. Sci.

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“…As acoustic waves can penetrate an opaque medium and be able to image the interior of structures, acoustic imaging is one of the best approaches to obtain the interior characteristics of objects. It is used as an important detection tool for medical diagnosis, [1][2][3][4] nondestructive testing, [5][6][7][8][9] sonar, [10][11][12][13][14] and so on. Conventional acoustic imaging is characterized by two features.…”

Section: Introductionmentioning

confidence: 99%

Frequency Representation: Visualization and Clustering of Acoustic Data Using Self-Organizing Maps

Guo

Sun

et al. 2017

Ultrason Imaging

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Extraction and display of frequency information in three-dimensional (3D) acoustic data are important steps to analyze object characteristics, because the characteristics, such as profiles, sizes, surface structures, and material properties, may show frequency dependence. In this study, frequency representation (FR) based on phase information in multispectral acoustic imaging (MSAI) is proposed to overcome the limit of intensity or amplitude information in image display. Experiments are performed on 3D acoustic data collected from a rigid surface engraved with five different letters. The results show that the proposed FR technique can not only identify the depth of the five letters by the colors representing frequency characteristics but also demonstrate the 3D image of the five letters, providing more detailed characteristics that are unavailable by conventional acoustic imaging.

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“…As sound waves travel with little attenuation in solids and fluids in which electromagnetic waves do not propagate, acoustic imaging techniques have been applied to many fields including underwater sound navigation and ranging (SONAR) [1][2][3][4][5], medical diagnosis [6][7][8] and nondestructive evaluation [9][10][11][12]. In general, the target object is illuminated by acoustic waves, and then the reflected or transmitted waves are recorded.…”

Section: Introductionmentioning

confidence: 99%

RGB representation of two-dimensional multi-spectral acoustic data for object surface profile imaging

Guo¹,

Wada²,

Mizuno³

et al. 2013

Meas. Sci. Technol.

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Conventionally, acoustic imaging has been performed using a single frequency or a limited number of frequencies. However, the rich information on surface profiles, structures hidden under surfaces and material properties of objects may exhibit frequency dependence. In this study, acoustic imaging on object surface was conducted over a wide frequency range with a fine frequency step, and a method for displaying the acquired multi-spectral acoustic data was proposed. A complicated rigid surface with different profiles was illuminated by sound waves sweeping over the frequency range from 1 to 20 kHz with a 30 Hz step. The reflected sound was two-dimensionally recorded using a scanning microphone, and processed using a holographic reconstruction method. The two-dimensional distributions of obtained sound pressure at each frequency were defined as 'multi-spectral acoustic imaging data'. Next, the multi-spectral acoustic data were transformed into a single RGB-based picture for easy understanding of the surface characteristics. The acoustic frequencies were allocated to red, green and blue using the RGB filter technique. The depths of the grooves were identified by their colours in the RGB image.

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Experimental investigation of several passive sonar targets

Cited by 20 publications

References 0 publications

A Portable Opto-Acoustic Survey Solution for Mapping of Underwater Targets

A Portable Opto-Acoustic Survey Solution for Mapping of Underwater Targets

Frequency Representation: Visualization and Clustering of Acoustic Data Using Self-Organizing Maps

RGB representation of two-dimensional multi-spectral acoustic data for object surface profile imaging

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