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V Asundi, Ravindra, Anusha L Narayanan, Archana B, Ananya H A, and C. Shrunga Divakara. "Sonar Interface with FCS and Target Detection." International Journal of Engineering & Technology 7, no. 3.12 (July 20, 2018): 541. http://dx.doi.org/10.14419/ijet.v7i3.12.16175.
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This paper presents a method to interface sound navigation and ranging(SONAR) with fire control system(FCS) and detection of targets. A submarine navigator keeps track of surrounding submarines and active targets such as torpedoes or mines and passive targets such as rocks, friend submarine or a ship, in order to have tactical information of its neighborhood. At present this is carried out manually by trained sonar operator. This task of classifying the object as either mines or rocks by training an artificial neural network using tensor flow framework, thereby giving the submarine (ship) system more autonomy.
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Satish, Aprameya, Brendan Nichols, David Trivett, and Karim G. Sabra. "Passive underwater acoustic markers for navigation and information encoding for high frequency sound navigation and ranging (SONAR) devices." Journal of the Acoustical Society of America 142, no. 4 (October 2017): 2731. http://dx.doi.org/10.1121/1.5014975.
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Rahmani, Mohamed Elhadi, Abdelmalek Amine, and Reda Mohamed Hamou. "Sonar Data Classification Using a New Algorithm Inspired from Black Holes Phenomenon." International Journal of Information Retrieval Research 8, no. 2 (April 2018): 25–39. http://dx.doi.org/10.4018/ijirr.2018040102.
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Sound Navigation and Ranging (Sonar) is underwater sound detection used in boats or submarines to navigate, communicate with or detect objects under the surface of water based on sound propagation. It is helpful for exploring and mapping the ocean because sound waves travel farther in the water than do radar and light waves. Based on signal data obtained from sonar, this article presents a new heuristic approach inspired from black holes' phenomenon proposed by Schwarzschild, it has been applied to the classification sonar returns from two undersea targets, a metal cylinder and a similarly-shaped rock. Results are very satisfied (almost 83% of accuracy) compared to original works. in manner that encourage to keep working on paper, the main idea of this article is to benefit from the power of nature to solve complex problems in computer science
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Novebriawan, Taufan, Luddy Andreas Delia, Endro Sigit Kurniawan, Kukuh Suryo, and Dikdik Satria Mulyadi. "Purwarupa Peralatan Pencitraan Bawah Laut Dilengkapi Penentu Posisi." Jurnal HIDROPILAR 6, no. 2 (April 6, 2021): 87–102. http://dx.doi.org/10.37875/hidropilar.v6i2.183.
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Sonar atau Sound Navigation and Ranging adalah teknik yang digunakan untuk menentukan posisi (jarak) menggunakan media gelombang suara. Sonar banyak dipakai untuk mengetahui situasi yang ada di dalam kolom air tertentu. Selain itu sonar juga berguna untuk mengukur jarak serta mencari atau mendeteksi suatu benda yang ada di bawah permukaan laut. Sonar bekerja dengan menggunakan prinsip mengirimkan gelombang suara dan akan dipantulkan kembali ketika gelombang tersebut mengenai suatu objek atau benda.
Dalam Tugas Akhir ini penulis bermaksud untuk mengembangkan purwarupa peralatan pencitraan bawah laut yang dilengkapi dengan penentu posisi. Hal ini merupakan salah satu usaha yang dilakukan dalam rangka mewujudkan kemandirian teknologi.
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Begum, Shaik Salma, Kandipalli Durga Prasanth, Kotapati Lasya Reddy, Kokkiligadda Sai Kumar, and Kancharla Jyotsna Nagasree. "RDNN for Classification and Prediction of Rock or Mine in Underwater Acoustics." International Journal on Recent and Innovation Trends in Computing and Communication 11, no. 3 (April 4, 2023): 98–104. http://dx.doi.org/10.17762/ijritcc.v11i3.6326.
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Mines in the waters are just explosives that detonate upon contact with an object. The underwater submarine must foresee if it will encounter a mine or a rock. Lacking the development of the Ranging Sound Navigation approach, which utilizes particular variables to identify whether a surface or a barrier is made of a mine or rock, finding mines or rocks would have been extremely difficult. In our study, we demonstrate a technique for predicting underwater rocks and mines using SONAR waves. At 60 different angles, SONAR pings are employed to record the various frequencies of submerged objects. To identify whether the object in the ocean is a mine or just a rock, the submarine uses SONAR signals, which transmit sound and receive switchbacks. The mine and rock categories are predicted using the prediction models. To create these prediction models, Supervised Machine Learning Classification methods were employed.
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Neupane, Dhiraj, and Jongwon Seok. "A Review on Deep Learning-Based Approaches for Automatic Sonar Target Recognition." Electronics 9, no. 11 (November 22, 2020): 1972. http://dx.doi.org/10.3390/electronics9111972.
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Underwater acoustics has been implemented mostly in the field of sound navigation and ranging (SONAR) procedures for submarine communication, the examination of maritime assets and environment surveying, target and object recognition, and measurement and study of acoustic sources in the underwater atmosphere. With the rapid development in science and technology, the advancement in sonar systems has increased, resulting in a decrement in underwater casualties. The sonar signal processing and automatic target recognition using sonar signals or imagery is itself a challenging process. Meanwhile, highly advanced data-driven machine-learning and deep learning-based methods are being implemented for acquiring several types of information from underwater sound data. This paper reviews the recent sonar automatic target recognition, tracking, or detection works using deep learning algorithms. A thorough study of the available works is done, and the operating procedure, results, and other necessary details regarding the data acquisition process, the dataset used, and the information regarding hyper-parameters is presented in this article. This paper will be of great assistance for upcoming scholars to start their work on sonar automatic target recognition.
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Elechi, Promise, Ela Okowa, and Osunomo Procter Illuma. "Analysis of a SONAR Detecting System Using Multi-Beamforming Algorithm." International Journal of Advanced Networking and Applications 14, no. 05 (2023): 5596–601. http://dx.doi.org/10.35444/ijana.2023.14503.
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Sonar (Sound Navigation and Ranging) system is an advanced underwater object-detecting system for navigation. The sonar system aids in detecting obstacles and the presence of enemies within a given range. The sonar system detects the targeted objects by identifying the radius and range of the targeted objects. One of the major problems that affect the application of the sonar system is the inability to detect objects due to excessive echoes and noise in the spectrum. The excessive echoes created reverberations that tend to distort the original reflected signal of the sonar system. This research aims to develop a sonar system that can detect a target object at 15km using a beamforming technique. The technique aids in creating a very high-level concentration on the objects by sending multiples of the same signals to one receiver, thereby reducing reverberation and transmission losses. The results show that 15 obstacles were detected at 15km, and reverberations were reduced by 2dB, thereby improving the visibility of the detected signal within its range with the lowest transmission loss of 0.5dB compared to the ultrasonic sonar system and the conventional echo object detecting system having a transmission loss of 3.12dB and 5.67dB respectively.
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Salambue, Roni. "PERANCANGAN ALAT PENGUKUR TINGGI BADAN DIGITAL DENGAN METODE SONAR." Rabit : Jurnal Teknologi dan Sistem Informasi Univrab 1, no. 1 (January 10, 2016): 31–36. http://dx.doi.org/10.36341/rabit.v1i1.14.
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Sonar is an abbreviation of (sound of ranging), which means the technique of spreading the sound for navigation and communicating or detecting other ships. Sonar can be applied to measure the distance of an object by reflecting ultrasonic waves to the object and then captured through the reciver. The ultrasonic wave is reflected by the SR04 sensor and uses Arduino Uno as a microcontroller where its distance is calculated. LCD is used to display measurement results so that it is easier to take height measurements. Arduino is a device that can be programmed and connected directly with an ultrasonic sensor used for measurements. The ultrasonic sensor is placed on a pole as high as 200 cm, and the distance of 200 cm is used as a benchmark measurement. Measurement using manual and digital can work well, but using digital level measurement speed is better than measuring using a manual.
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Park, Beom Hoon, Han Bin Choi, Hee-Seon Seo, Yub Je, Hak Yi, and Kwan Kyu Park. "Development of Multilayer Transducer and Omnidirectional Reflection Model for Active Reflection Control." Sensors 23, no. 1 (January 3, 2023): 521. http://dx.doi.org/10.3390/s23010521.
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Underwater detection is accomplished using an underwater ultrasonic sensor, sound navigation and ranging (SONAR). Stealth to avoid detection by SONAR plays a major role in modern underwater warfare. In this study, we propose a smart skin that avoids detection by SONAR via controlling the signal reflected from an unmanned underwater vehicle (UUV). The smart skin is a multilayer transducer composed of an acoustic window, a double-layer receiver, and a single-layer transmitter. It separates the incident signal from the reflected signal from outside through the time-delay separation method and cancels the reflected wave from the phase-shifted transmission sound. The characteristics of the receiving and transmitting sensors were analyzed using a finite element analysis. Three types of devices were compared in the design of the sensors. Polyvinylidene fluoride (PVDF), which had little effect on the transmitted sound, was selected as the receiving sensor. A stacked piezoelectric transducer with high sensitivity compared to a cymbal transducer was used as the transmitter. The active reflection control system was modeled and verified using 2D 360° reflection experiments. The stealth effect that could be achieved by applying a smart skin to a UUV was presented through an active reflection–control omnidirectional reflection model.
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Jang, Jejin, Jaehyuk Choi, Donghun Lee, and Hyungsoo Mok. "Estimation Method of an Electrical Equivalent Circuit for Sonar Transducer Impedance Characteristic of Multiple Resonance." Sensors 23, no. 14 (July 24, 2023): 6636. http://dx.doi.org/10.3390/s23146636.
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Improving the operational efficiency and optimizing the design of sound navigation and ranging (sonar) systems require accurate electrical equivalent models within the operating frequency range. The power conversion system within the sonar system increases power efficiency through impedance-matching circuits. Impedance matching is used to enhance the power transmission efficiency of the sonar system. Therefore, to increase the efficiency of the sonar system, an electrical-matching circuit is employed, and this necessitates an accurate equivalent circuit for the sonar transducer within the operating frequency range. In conventional equivalent circuit derivation methods, errors occur because they utilize the same number of RLC branches as the resonant frequency of the sonar transducer, based on its physical properties. Hence, this paper proposes an algorithm for deriving an equivalent circuit independent of resonance by employing multiple electrical components and particle swarm optimization (PSO). A comparative verification was also performed between the proposed and existing approaches using the Butterworth–van Dyke (BVD) model, which is a method for deriving electrical equivalent circuits.
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N., Mohan Kumar, Vinutha Patil, Varshini P., and Chaitra K. M. "Two dimensional echocardiography as an evidence for clinically significant murmur." International Journal of Contemporary Pediatrics 9, no. 2 (January 24, 2022): 163. http://dx.doi.org/10.18203/2349-3291.ijcp20220087.
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Background: Heart murmurs are extra and abnormal sounds made by turbulent flow of blood through heart. The most common cardiac abnormality found on auscultation is murmur. Edler is regarded as father of echocardiography. This is based on reflection of sound waves by heart structures similar to the radio detection and ranging (RADAR) and sound navigation and ranging (SONAR).Methods: Our study was done in PICU of Kempegowda Institute of Medical Sciences hospital, Bangalore. Duration of study was 6 years that is from January 2015 to January 2020. During this period total 2304 pediatric cases with various diseases were admitted. Of these 150 (6.5%) children were having clinically significant murmur. All children who fulfilled inclusion criteria were subjected to 2d echo by GE VIVID portable 2 dimensional and colour Doppler echocardiography trans-thoracically.Results: 96 (64%) children had abnormal 2d echo. Of these 37 (38.5%) children were found to have organic heart disease and 59 (61.5%) had functional heart disease. Of these 37 children 10 (27%) had pulmonary arterial hypertension (PAH), 8 (21%) children had atrial septal defect, 7 (18%) had perforated foramen ovale (PFO), 2 (5%) had mitral valve prolapse, 2 (5%) had ventricular septal defect (VSD), 1(2%) had tetralogy of fallot (TOF), 1 (2%) had septal aneurysm, and 1 (2%) had pericardial effusion.Conclusions: There is 64% chances of detecting a heart disease, if 2D echo is done in children with clinically significant cardiac murmur. Hence 2D echo is a vital investigation in evaluating heart murmurs.
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Sathish, Kaveripakam, Rajesh Anbazhagan, Ravikumar Chinthaginjala Venkata, Fabio Arena, and Giovanni Pau. "Investigation and Numerical Simulation of the Acoustic Target Strength of the Underwater Submarine Vehicle." Inventions 7, no. 4 (December 1, 2022): 111. http://dx.doi.org/10.3390/inventions7040111.
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Modern weapon systems’ survival hinges on their detection capabilities more than anything else. In the active sonar equation, the acoustic target strength is crucial. Under the assumption of plane wave propagation, the standard target strength equation is used to forecast the reradiated intensity for the far field. The ability of a submarine to remain unnoticed while on patrol or accomplishing a mission is its primary defense. Sonar, sometimes known as sound navigation ranging, is a popular method for locating submarines. This is because saltwater effectively absorbs radio frequencies. Sonar technology is used in more than just the commercial fishing business; it is also used in undersea research. The submarine’s designers consider the reflection of acoustic waves to minimize the amount of space required for such reflections. The Target Strength (TS) metric is used to assess the sonar objects’ size. This manuscript explains and demystifies the Benchmark Target Echo Strength Simulation (BeTTSi) benchmark submarine’s TS analysis. This model’s Pressure Acoustic-Boundary Element Model (PA-BEM) interface has been stabilized, and the model itself is pretty huge acoustically.
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Reitmann, Stefan, Lorenzo Neumann, and Bernhard Jung. "BLAINDER—A Blender AI Add-On for Generation of Semantically Labeled Depth-Sensing Data." Sensors 21, no. 6 (March 18, 2021): 2144. http://dx.doi.org/10.3390/s21062144.
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Common Machine-Learning (ML) approaches for scene classification require a large amount of training data. However, for classification of depth sensor data, in contrast to image data, relatively few databases are publicly available and manual generation of semantically labeled 3D point clouds is an even more time-consuming task. To simplify the training data generation process for a wide range of domains, we have developed the BLAINDER add-on package for the open-source 3D modeling software Blender, which enables a largely automated generation of semantically annotated point-cloud data in virtual 3D environments. In this paper, we focus on classical depth-sensing techniques Light Detection and Ranging (LiDAR) and Sound Navigation and Ranging (Sonar). Within the BLAINDER add-on, different depth sensors can be loaded from presets, customized sensors can be implemented and different environmental conditions (e.g., influence of rain, dust) can be simulated. The semantically labeled data can be exported to various 2D and 3D formats and are thus optimized for different ML applications and visualizations. In addition, semantically labeled images can be exported using the rendering functionalities of Blender.
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Kim, Won-Ki, Ho Seuk Bae, Su-Uk Son, and Joung-Soo Park. "Neural Network-Based Underwater Object Detection off the Coast of the Korean Peninsula." Journal of Marine Science and Engineering 10, no. 10 (October 5, 2022): 1436. http://dx.doi.org/10.3390/jmse10101436.
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Recently, neural network-based deep learning techniques have been actively applied to detect underwater objects in sonar (sound navigation and ranging) images. However, unlike optical images, acquiring sonar images is extremely time- and cost-intensive, and therefore securing sonar data and conducting related research can be rather challenging. Here, a side-scan sonar was used to obtain sonar images to detect underwater objects off the coast of the Korean Peninsula. For the detection experiments, we used an underwater mock-up model with a similar size, shape, material, and acoustic characteristics to the target object that we wished to detect. We acquired various side-scan sonar images of the mock-up object against the background of mud, sand, and rock to account for the different characteristics of the coastal and seafloor environments of the Korean Peninsula. To construct a detection network suitable for the obtained sonar images from the experiment, the performance of five types of feature extraction networks and two types of optimizers was analyzed. From the analysis results, it was confirmed that performance was achieved when DarkNet-19 was used as the feature extraction network, and ADAM was applied as the optimizer. However, it is possible that there are feature extraction network and optimizer that are more suitable for our sonar images. Therefore, further research is needed. In addition, it is expected that the performance of the modified detection network can be more improved if additional images are obtained.
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Choi, Jae-Hyuk, and Hyung-Soo Mok. "Simultaneous Design of Low-Pass Filter with Impedance Matching Transformer for SONAR Transducer Using Particle Swarm Optimization." Energies 12, no. 24 (December 6, 2019): 4646. http://dx.doi.org/10.3390/en12244646.
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Sound navigation and ranging (SONAR) systems detect a target in the front direction by using acoustic signals. A switching-type power conversion system is used to improve power efficiency, and an impedance matching circuit is used to decrease reactive power. A low-pass filter is used to improve the quality of acoustic signals. To achieve the desired voltage level for a SONAR transducer, a transformer is connected in series with a low-pass filter. In conventional design methods, design value errors occur because the components are designed independently and later combined. Moreover, if parameters that considerably impact operating characteristics are ignored in the design process, these errors will increase. Hence, time and cost losses are incurred during refabrication because operational characteristics differ from design values. To solve this problem, this study proposes the simultaneous design of a low-pass filter and impedance matching circuit, which includes critical design parameters, utilizing the particle swarm optimization algorithm. Moreover, conventional design methods were examined, and the superiority of the proposed design method to conventional methods was verified through analyses and experiments in terms of overall impedance phase and filter blocking characteristics.
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Villalobos, Ricardo, Héctor López, Nimrod Vázquez, Roberto V. Carrillo-Serrano, and Alejandro Espinosa-Calderón. "Cavitation Detection in a Tonpilz-Type Transducer for Active SONAR Transmission System." Journal of Marine Science and Engineering 11, no. 7 (June 24, 2023): 1279. http://dx.doi.org/10.3390/jmse11071279.
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The active sound navigation and ranging (SONAR) transmission system emits acoustic pulses underwater using a wave generator, a SONAR power amplifier (SPA), and a projector. The acoustic pulse travel in the direction of the target and return as an echo to a hydrophone to learn the range or speed of the object. Often the same device is used as a hydrophone and a projector; in this context, it is known as a transducer. In order to obtain a maximum range of detection in the SONAR, it is desirable to generate the maximum amount of acoustic power until the point in which the echo can be detectable in an atmosphere with non-wished noise. Therefore, a high value of source level (SL) is required that depends largely on the value of electrical power applied to the transducer (Pe). However, when trying to obtain the maximum range of detection in the SONAR system there are the following three peculiar limitations that affect performance: The cavitation, the reverberation, and the effect of interaction in the near field. In this paper, an experimental measurement methodology is presented to detect the cavitation effects in a tonpilz-type transducer for an active SONAR transmission system using a transducer as a projector and a calibrated hydrophone in a hydroacoustic tank by measuring the parameters of total harmonic distortion of the fundamental waveform (THD-F) of the generated acoustic pulse, transmitting voltage response (TVR) to characterize the system and sound pressure level (SPL) that indicates the intensity of sound at a given distance. Whereas the reverberation and the interaction effect in the near field are objects of other study cases. A 570.21 W and THD-F < 5% switched-mode power amplifier (SMPA) prototype was developed to excite the electroacoustic transducer employing a full-bridge inverter (FBI) topology and a digital controller using a field-programmable gate array (FPGA) for unipolar sine pulse width modulation (SPWM) to generate a continuous wave (CW) acoustic pulse at a frequency 11.6 kHz. The results obtained show that from the level of Pe=196.05 W with the transducer at 1 m of depth, the value of THD-F increases significantly while the behavior of the TVR and SPL parameters is affected since it is not as expected and is attributed when cavitation occurs.
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Kim, Min-Kyu, Dong-Jin Park, Yeong-Seok Oh, Jong-Hwa Kim, and Jin-Kyu Choi. "Towfish Attitude Control: A Consideration of Towing Point, Center of Gravity, and Towing Speed." Journal of Marine Science and Engineering 9, no. 6 (June 9, 2021): 641. http://dx.doi.org/10.3390/jmse9060641.
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This paper deals with the attitude control of a towfish (underwater towed vehicle) with two elevators and a single rudder to improve the image quality of an attached sound navigation ranging (sonar) system. Image distortion can occur if the towfish shakes excessively. Since a towfish is connected to the mother ship through a towing cable and the motion of the towfish is affected not only by the motion of the cable, but also by the position of the center of gravity, towing point, and towing speed, it is necessary to analyze how these factors affect the towfish to appropriately control its attitude. In this study, a method for obtaining a feasible region of the towing point in accordance with the variations in the center of gravity and towing speed is proposed, and the feasible region obtained can ensure that pitch control can be achieved using the installed elevators. In addition, the allowable range of disturbances for yaw control was also investigated. Simulations were conducted using the dynamic models of the towfish and cable to check the obtained feasible region/range, and it was confirmed that there is a region/range where the attitude control can be carried out with relative ease.
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Kamolov, Ahmadhon Akbarkhonovich, and Suhyun Park. "Prediction of Depth of Seawater Using Fuzzy C-Means Clustering Algorithm of Crowdsourced SONAR Data." Sustainability 13, no. 11 (May 21, 2021): 5823. http://dx.doi.org/10.3390/su13115823.
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Implementing AI in all fields is a solution to the complications that can be troublesome to solve for human beings and will be the key point of the advancement of those spheres. In the marine world, specialists also encounter some problems that can be revealed through addressing AI and machine learning algorithms. One of these challenges is determining the depth of the seabed with high precision. The depth of the seabed is utterly significant in the procedure of ships at sea occupying a safe route. Thus, it is considerably crucial that the ships do not sit in shallow water. In this article, we have addressed the fuzzy c-means (FCM) clustering algorithm, which is one of the vigorous unsupervised learning methods under machine learning to solve the mentioned problems. In the case study, crowdsourced data have been trained, which are gathered from vessels that have installed sound navigation and ranging (SONAR) sensors. The data for the training were collected from ships sailing in the south part of South Korea. In the training section, we segregated the training zone into the diminutive size areas (blocks). The data assembled in blocks had been trained in FCM. As a result, we have received data separated into clusters that can be supportive to differentiate data. The results of the effort show that FCM can be implemented and obtain accurate results on crowdsourced bathymetry.
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Jin, Meng, Yuqi Bai, Emmanuel Devys, and Liping Di. "Toward a Standardized Encoding of Remote Sensing Geo-Positioning Sensor Models." Remote Sensing 12, no. 9 (May 11, 2020): 1530. http://dx.doi.org/10.3390/rs12091530.
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Geolocation information is an important feature of remote sensing image data that is captured through a variety of passive or active observation sensors, such as push-broom electro-optical sensor, synthetic aperture radar (SAR), light detection and ranging (LIDAR) and sound navigation and ranging (SONAR). As a fundamental processing step to locate an image, geo-positioning is used to determine the ground coordinates of an object from image coordinates. A variety of sensor models have been created to describe geo-positioning process. In particular, Open Geospatial Consortium (OGC) has defined the Sensor Model Language (SensorML) specification in its Sensor Web Enablement (SWE) initiative to describe sensors including the geo-positioning process. It has been realized using syntax from the extensible markup language (XML). Besides, two standards defined by the International Organization for Standardization (ISO), ISO 19130-1 and ISO 19130-2, introduced a physical sensor model, a true replacement model, and a correspondence model for the geo-positioning process. However, a standardized encoding for geo-positioning sensor models is still missing for the remote sensing community. Thus, the interoperability of remote sensing data between application systems cannot be ensured. In this paper, a standardized encoding of remote sensing geo-positioning sensor models is introduced. It is semantically based on ISO 19130-1 and ISO 19130-2, and syntactically based on OGC SensorML. It defines a cross mapping of the sensor models defined in ISO 19130-1 and ISO 19130-2 to the SensorML, and then proposes a detailed encoding method to finalize the XML schema (an XML schema here is the structure to define an XML document), which will become a profile of OGC SensorML. It seamlessly unifies the sensor models defined in ISO 19130-1, ISO 19130-2, and OGC SensorML. By enabling a standardized description of sensor models used to produce remote sensing data, this standard is very promising in promoting data interoperability, mobility, and integration in the remote sensing domain.
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Razzaq, Huda Saleem, and Zahir M. Hussain. "Instantaneous Frequency Estimation of FM Signals under Gaussian and Symmetric α-Stable Noise: Deep Learning versus Time–Frequency Analysis." Information 14, no. 1 (December 28, 2022): 18. http://dx.doi.org/10.3390/info14010018.
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Deep learning (DL) and machine learning (ML) are widely used in many fields but rarely used in the frequency estimation (FE) and slope estimation (SE) of signals. Frequency and slope estimation for frequency-modulated (FM) and single-tone sinusoidal signals are essential in various applications, such as wireless communications, sound navigation and ranging (SONAR), and radio detection and ranging (RADAR) measurements. This work proposed a novel frequency estimation technique for instantaneous linear FM (LFM) sinusoidal wave using deep learning. Deep neural networks (DNN) and convolutional neural networks (CNN) are classes of artificial neural networks (ANNs) used for the frequency and slope estimation for LFM signals under additive white Gaussian noise (AWGN) and additive symmetric alpha stable noise (SαSN). DNN is composed of input, output, and two hidden layers, where several nodes in the first and second hidden layers are 25 and 8, respectively. CNN is the content input layer; many hidden layers include convolution, batch normalization, ReLU, max pooling, fully connected, and dropout. The output layer consists of a fully connected softmax and classification layers. SαS distributions are impulsive noise disturbances found in many communication environments such as marine systems, their distribution lacks a closed-form probability density function (PDF), except for specific cases, and infinite second-order statistics, hence geometric SNR (GSNR) is used in this work to determine the effect of noise in a mixture of Gaussian and SαS noise processes. DNN is a machine learning classifier with few layers for reducing FE and SE complexity. CNN is a deep learning classifier, designed with many layers, and proved to be more accurate than DNN when dealing with big data and finding optimal features. Simulation results show that SαS noise can be much more harmful to the FE and SE of FM signals than Gaussian noise. DL and ML can significantly reduce FE complexity, memory cost, and power consumption as compared to the classical FE based on time–frequency analysis, which are important requirements for many systems, such as some Internet of Things (IoT) sensor applications. After training CNN for frequency and slope estimation of LFM signals, the performance of CNN (in terms of accuracy) can give good results at very low signal-to-noise ratios where time–frequency distribution (TFD) fails, giving more than 20 dB difference in the GSNR working range as compared to the classical spectrogram-based estimation, and over 15 dB difference with Viterbi-based estimate.
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Vojinovic, Z., Y. A. Abebe, R. Ranasinghe, A. Vacher, P. Martens, D. J. Mandl, S. W. Frye, E. van Ettinger, and R. de Zeeuw. "A machine learning approach for estimation of shallow water depths from optical satellite images and sonar measurements." Journal of Hydroinformatics 15, no. 4 (May 15, 2013): 1408–24. http://dx.doi.org/10.2166/hydro.2013.234.
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There has been a rapid growth in the field of remote sensing and its various applications in the area of water management. Nowadays, there are several remote sensing techniques that can be used as a source to derive bathymetry data along coastal areas. The key techniques are: sonar (sound navigating and ranging), LiDAR (light detection and ranging) and high-resolution satellite images. The present paper describes a method which was developed and used to create a shallow water bathymetry data along the Dutch side of Sint Maarten Island by combining sonar measurements and satellite images in a nonlinear machine learning technique. The purpose of this work is to develop a bathymetry dataset that can be used to set up physically-based models for coastal flood modelling work. The nonlinear machine learning technique used in the work is a support vector machine (SVM) model. The sonar data were used as an output whereas image data were used as an input into the SVM model. The results were analysed for three depth ranges and the findings are promising. It remains to further verify the capacity of the new method on a dataset with higher resolution satellite imagery.
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Schmidt, Henrik. "Environmentally adaptive acoustic communication and navigation for underice autonomous operation." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A109. http://dx.doi.org/10.1121/10.0015709.
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The Arctic acoustic environment has changed dramatically, with multi-year ice being less abundant and the influx of warmer Pacific water, the so-called “Beaufort Lens,” creating a local maximum in the sound speed at a depth of 50–80 m. In contrast to the classic Arctic sound speed profile which had a monotonic increase in sound speed yielding a surface duct with strong ice interaction, the warm water lens creates a lower duct supporting extremely efficient propagation to long ranges. On the other hand, this double duct environment is decremental to short range communication and navigation of underwater vehicles. Thus, for a transmitter in one channel, the lens creates distinct shadow zones in the other channel at ranges between 1 and 4 km, which are the typical operational ranges of small AUVs, severely affecting navigation and communication performance. In addition, the temporal variability of is significant due to internal waves. During ICEX20 MIT and WHOI demonstrated an integrated communication and navigation concept where a network of ice-moored modem buoys with GPS tracking were used to track an under-ice AUV using regular CTD updates of optimal ranging, which in combination with a novel dynamic model constrained navigation fusion engine demonstrating GPS-grade navigation accuracy over several hours of operation. Using an EOF framework for updating the onboard environmental awareness on the AUV, the concept supports autonomous depth selection for optimal communication connectivity. [Work supported by ONR and UWDC/ASL.]
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Sivle, Lise Doksæter, Petter Helgevold Kvadsheim, Michael A. Ainslie, Andrew Solow, Nils Olav Handegard, Nina Nordlund, and Frans-Peter A. Lam. "Impact of naval sonar signals on Atlantic herring (Clupea harengus) during summer feeding." ICES Journal of Marine Science 69, no. 6 (May 14, 2012): 1078–85. http://dx.doi.org/10.1093/icesjms/fss080.
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Abstract Sivle, L. D., Kvadsheim, P. H., Ainslie, M. A., Solow, A., Handegard, N. O. Nordlund, N., and Lam, F-P. A. 2012. Impact of naval sonar signals on Atlantic herring (Clupea harengus) during summer feeding. – ICES Journal of Marine Science, 69: 1078–1085. Naval anti-submarine sonars produce intense sounds within the hearing range of Atlantic herring (Clupea harengus). In this study, schools of Atlantic herring were exposed to sonar signals of 1–2 kHz (low-frequency active sonar, LFAS) and 6–7 kHz (mid-frequency active sonar, MFAS) and playbacks of killer whale feeding sounds during their summer feeding migration in the Norwegian Sea. The fish schools neither significantly dived nor changed their packing density in response to the LFAS and MFAS transmissions received by the fish at estimated sound pressure levels (SPLs; RMS) up to 176 and 157 dB re 1 μPa and estimated cumulative sound exposure levels up to 181 and 162 dB re 1 μPa² s, respectively. In contrast, killer whale feeding sounds induced diving responses at received SPLs at ∼150 dB re 1 μPa. Herring behaviour was studied by using a 116-kHz hull mounted fishery sonar. This seems a promising method for studying the behaviour of free-ranging fish in situations in which other methods are difficult to use, such as migrating schools and fish close to the surface.
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Curé, Charlotte, Saana Isojunno, Marije L. Siemensma, Paul J. Wensveen, Célia Buisson, Lise D. Sivle, Benjamin Benti, et al. "Severity Scoring of Behavioral Responses of Sperm Whales (Physeter macrocephalus) to Novel Continuous versus Conventional Pulsed Active Sonar." Journal of Marine Science and Engineering 9, no. 4 (April 19, 2021): 444. http://dx.doi.org/10.3390/jmse9040444.
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Controlled exposure experiments (CEEs) have demonstrated that naval pulsed active sonar (PAS) can induce costly behavioral responses in cetaceans similar to antipredator responses. New generation continuous active sonars (CAS) emit lower amplitude levels but more continuous signals. We conducted CEEs with PAS, CAS and no-sonar control on free-ranging sperm whales in Norway. Two panels blind to experimental conditions concurrently inspected acoustic-and-movement-tag data and visual observations of tagged whales and used an established severity scale (0–9) to assign scores to putative responses. Only half of the exposures elicited a response, indicating overall low responsiveness in sperm whales. Responding whales (10 of 12) showed more, and more severe responses to sonar compared to no-sonar. Moreover, the probability of response increased when whales were previously exposed to presence of predatory and/or competing killer or long-finned pilot whales. Various behavioral change types occurred over a broad range of severities (1–6) during CAS and PAS. When combining all behavioral types, the proportion of responses to CAS was significantly higher than no-sonar but not different from PAS. Responses potentially impacting vital rates i.e., with severity ≥4, were initiated at received cumulative sound exposure levels (dB re 1 μPa2 s) of 137–177 during CAS and 143–181 during PAS.
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Nyeon Kim, Jeong, Tianning Liu, Thomas N. Jackson, Kyusun Choi, Susan Trolier-McKinstry, Richard L. Tutwiler, and Judith A. Todd. "Design and Ultrasonic Characterization of a Thin-Film, Flexible, PMUT Array." AM&P Technical Articles 178, no. 8 (November 1, 2020): 15–20. http://dx.doi.org/10.31399/asm.amp.2020-08.p015.
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Abstract Ultrasound is widely used for nondestructive evaluation, structural health monitoring, acoustic emission, sound navigation ranging, and in sensors for automobiles, medicine, and many other applications. Next-generation, small-form-factor sensors have been achieved through advances in piezoelectric micromachined ultrasonic transducers (PMUTs) that can be positioned on either a flexible polymer or a silicon substrate to form an array. This article describes a materials and design optimization study that used finite element analyses to improve designs for robust and practical PMUT sensor arrays.
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Kapoor, Rohan, Alessandro Gardi, and Roberto Sabatini. "Network Optimisation and Performance Analysis of a Multistatic Acoustic Navigation Sensor." Sensors 20, no. 19 (October 8, 2020): 5718. http://dx.doi.org/10.3390/s20195718.
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This paper addresses some of the existing research gaps in the practical use of acoustic waves for navigation of autonomous air and surface vehicles. After providing a characterisation of ultrasonic transducers, a multistatic sensor arrangement is discussed, with multiple transmitters broadcasting their respective signals in a round-robin fashion, following a time division multiple access (TDMA) scheme. In particular, an optimisation methodology for the placement of transmitters in a given test volume is presented with the objective of minimizing the position dilution of precision (PDOP) and maximizing the sensor availability. Additionally, the contribution of platform dynamics to positioning error is also analysed in order to support future ground and flight vehicle test activities. Results are presented of both theoretical and experimental data analysis performed to determine the positioning accuracy attainable from the proposed multistatic acoustic navigation sensor. In particular, the ranging errors due to signal delays and attenuation of sound waves in air are analytically derived, and static indoor positioning tests are performed to determine the positioning accuracy attainable with different transmitter–receiver-relative geometries. Additionally, it is shown that the proposed transmitter placement optimisation methodology leads to increased accuracy and better coverage in an indoor environment, where the required position, velocity, and time (PVT) data cannot be delivered by satellite-based navigation systems.
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Bhatt, EeShan, Robert A. Weller, and Arthur B. Baggeroer. "Evaluating the impact of intermediate and deep sound speed uncertainty in the Irminger Sea on acoustic situational awareness." Journal of the Acoustical Society of America 152, no. 4 (October 2022): A200. http://dx.doi.org/10.1121/10.0016024.
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High-resolution observations from moorings and transect data can provide new insights into ocean structures, their variability, and the downstream effects on acoustic operations. Previously, we established a framework to maintain optimal communication and navigation for small-scale, under-ice operations that focused on spatio-temporal variability in the upper water column and around an autonomous underwater vehicle. However, mid- and deep-water sound speed fidelity are crucial for larger operations that exploit convergence zone ranging. The Irminger Sea is a useful case study for understanding how sound speed uncertainty, whether from partial data or models, obscures the informational content from acoustics. Generally, the density gradient dominates the sound speed at depth. In the Irminger Sea, hydrographic variability comes from the advection of different water masses through the region at all depths and also from water mass modification by local air-sea interaction. Instead of a uniform gradient as a result of hydrostatic loading, a shifted gradient in the mid-water column and a negative gradient near the bottom are often observed in mooring and transect data. This talk presents initial results for understanding the impacts of the environment through the lens of impact on acoustic propagation. [Work supported by the Office of Naval Research]
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Сорокин, М. А., П. С. Петров, Д. Д. Каплуненко, Д. В. Степанов, and Ю. Н. Моргунов. "ESTIMATION OF THE SYNOPTIC EDDIES INFLUENCE ON THE ACOUSTIC RANGING ACCURACY." Podvodnye issledovaniia i robototehnika, no. 4(34) (January 24, 2020): 53–60. http://dx.doi.org/10.37102/24094609.2020.34.4.007.
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Разработка систем акустической навигации и акустической дальнометрии в настоящее время является одной из наиболее актуальных практических задач акустики океана. В работе исследуется вопрос о влиянии крупномасштабных неоднородностей поля скорости звука в океане на точность решения задачи акустической дальнометрии. В качестве примера такой неоднородности нами выбран устойчивый антициклонический вихрь, наблюдающийся в южной части Японского моря в летний период. В работе проведены вычислительные эксперименты по исследованию влияния этого вихря на структуру звукового поля, формируемого на акустической трассе, проходящей через его центр, источником навигационных сигналов (ИНС), расположенным на шельфе. В ходе этих экспериментов по гидрологическим данным, полученным с помощью моделей глобальной циркуляции океана NEMO и ИВМ РАН, для этой трассы построена модель нерегулярного волновода «шельф–глубокий океан», после чего с помощью метода широкоугольных параболических уравнений выполнено моделирование акустического поля, формируемого ИНС в таком волноводе. Далее в работе также выполнен анализ модовой структуры этого поля, определены интервалы локализации различных модальных компонент сигнала и рассчитаны эффективные скорости распространения сигналов от ИНС на различных горизонтах приема, после чего исследовано влияние синоптического вихря на данные характеристики волновода. На основе этого анализа выполнены оценки влияния вихря на времена прихода сигналов от ИНС в точку приема, а также дополнительная погрешность решения задачи акустической дальнометрии, обусловленная этим влиянием. Результаты исследования показывают, что в рамках рассматриваемой методики решения задачи акустической дальнометрии даже относительно крупный неучтенный синоптический вихрь, ядро которого находится непосредственно на трассе, оказывает относительно слабое влияние на точность определения дальности (около 30 м для трассы протяженностью 300 км, или 0,01%). The development of acoustic navigation and acoustic ranging systems is currently one of the most important practical problems of ocean acoustics. In this study, the influence of large-scale inhomogeneities on the sound speed field in the ocean on the accuracy of acoustic ranging problem solution is considered. As a representative example of an inhomogeneity of this kind, we chose a stable anticyclonic eddy that is observed in the southern part of the sea of Japan in summer. In this work, computational experiments are conducted in order to study the influence of this eddy on the structure of the sound field formed along an acoustic path passing through the eddy's center by a source of navigation signals (SNS) located on the shelf. In the course of these experiments, a model of a range-dependent "shallow-to-deep-sea" waveguide was constructed along this path using hydrological data obtained from NEMO and INM RAS global ocean circulation models. After that, the acoustic field produced by the SNS in this waveguide was simulated by the method of wide-angle parabolic equations. The mode structure of the field along the path is studied, localization intervals of various modal components of the signal are determined, and the effective propagation velocities of signals transmitted by SNS are calculated at various reception horizons. The influence of the synoptic eddy on these waveguide characteristics is also investigated. On the basis of this analysis, the effect of the eddy on arrival times of the signals propagating from the SNS to the reception point is estimated, as well as the additional error in the solution of acoustic ranging problem caused by the presence of the eddy. The results of the study show, that within the framework of the considered technique of acoustic ranging problem solution, even the presence of a large unaccounted synoptic eddy, with its core located directly on the acoustic path, has a relatively weak effect on the accuracy of range estimation (about 30 m for a path 300 km long, or 0,01%).
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Ramesh, Raju, Dharmaraj Sathianarayanan, Vittal Doss Prakash, Arumugam Vadivelan, Sethuraman Ramesh, Gidugu Ananda Ramadass, and Malayath Aravindakshan Atmanand. "Failure Analysis of Fiber Optic Communication System in Deep-Water Remotely Operated Vehicle ROSUB 6000." Marine Technology Society Journal 48, no. 3 (May 1, 2014): 63–72. http://dx.doi.org/10.4031/mtsj.48.3.11.
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AbstractSingle-mode fiber optic systems can play vital roles in cabled deep-water vehicle operations at greater depths (>3,000 m). One kind of single-mode fiber optic system, the ROSUB 6000, is used in a deep-water work-class remotely operated vehicle (ROV). Fiber optic link failure of ROV telemetry and sound navigation and ranging were noticed at a water depth of 3,050 m during the ROSUB 6000 system sea trials. A failure analysis of the fiber optic communication system was carried out with the link data logged during different phases of the deep-sea trials. The results from the failure analysis carried out during deep-sea trials showed an increase in the fiber optic link loss from a depth of 900 m onwards. Further analysis of the fiber optic link loss in the laboratory involved pressure and low-temperature testing of all the subsea components in the ROV telemetry link. From the laboratory pressure test results, it was concluded that pressure was not the root cause of the fiber optic link failure. On further analysis, a complete fiber optic link failure was noticed during the low-temperature testing of the subsea components. Furthermore, the low-temperature testing of the individual subsea components revealed that the fiber optic rotary joint (FORJ) insertion loss increased rapidly at low temperatures. This FORJ insertion loss led to complete failure of the fiber optic links in the ROV. The degradation of index-matching fluid in the FORJ was identified to be the root cause of fiber link failure.
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"Designing of Low Cost Arduino Based Ultrasonic SONAR System." VFAST Transactions on Software Engineering, November 1, 2017, 57–65. http://dx.doi.org/10.21015/vtse.v12i3.505.
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Sonar (Sound Navigation and Ranging) was covertly created by few countries during the reign of World War II. SONAR can be used to detect some moving object. It helps in the measurement of distance and angle from the observer. It works on the principle of Doppler shift. The designing of cheaper SONAR system for security purpose is the requirement of an industry. In this research Paper, the designing and implementation of Arduino based SONAR system using ultrasonic sensor are presented. The device is able to detect the object, calculate its distance (up to 30cm) and can determine the elevation angle. It provides a cheaper solution for security purposes.
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Giraldo E., Carlos. "Principios básicos de ultrasonografía veterinaria." Revista MVZ Córdoba, July 1, 2003. http://dx.doi.org/10.21897/rmvz.508.
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La tecnología del ultrasonido nace en 1880 con el desarrollo de los efectos piezoeléctricos. Luego fue aplicada en forma de SONAR (Sound Navigation and Ranging) durante la segunda guerra mundial para la detección de barcos, submarinos y aviones de guerra. La emisión de las ondas de ultrasonido se obtiene por medio de cristales que son sometidos a una corriente eléctrica logrando que vibren, la recepción de éstas ondas se logra cuando retornan de nuevo a los cristales al chocar con los tejidos. Estos cristales están contenidos en dispositivos llamados transductores o sondas ecográficas conectadas a un monitor. (Perkings 2000, Ginther et al. 1989)
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Bowers, Gerald M. "Military Contributions to the Field of Medical Ultrasound." Military Medicine, August 29, 2022. http://dx.doi.org/10.1093/milmed/usac262.
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ABSTRACT Medical ultrasound is based on the same principle of the piezoelectric effect as sound navigation and ranging, used by the world’s navies and maritime industry. Many of the early advances in sound navigation and ranging technology influenced landmark discoveries in diagnostic ultrasound made by military officers and defense department researchers.
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Shiga, John. "Sonar: Empire, Media, and the Politics of Underwater Sound." Canadian Journal of Communication 38, no. 3 (September 14, 2013). http://dx.doi.org/10.22230/cjc.2013v38n3a2664.
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This article traces the development of acoustic navigation media, or “sonar,” in the first half of the twentieth century, focusing on the relationships forged between underwater sound, electric media, and new techniques of listening. The central argument is that sonar shaped, and was shaped by, the expansion of warfare and capital underwater, and that this expansion came to be conceptualized by nautical organizations as dependent upon the control of underwater sound. Through analysis of key episodes in the conquest of subsea space, the author explores scientific, military, and commercial efforts to sense underwater objects and demonstrates how these efforts helped reconceptualize oceanic water as a component of undersea acoustic media and led to the material reorganization of the ocean’s acoustic field.Cet article retrace le développement de médias acoustiques de navigation ou « sonars » dans la première moitié du vingtième siècle en mettant l’accent sur les rapports créés entre les sons sous-marins, les médias électriques et les nouvelles techniques d’écoute. L’argument central de l’article est qu’il y a eu une influence réciproque entre le sonar et l’expansion sous-marine de la guerre et du capital, et que les organisations nautiques ont commencé à concevoir cette expansion comme nécessitant le contrôle des sons sous-marins. Au moyen d’une analyse d’épisodes clés dans la conquête de l’espace sous-marin, l’auteur explore les efforts scientifiques, militaires et commerciaux pour repérer les objets sous l’eau et démontre comment ces efforts ont aidé à réaliser une nouvelle conception de l’eau océanique comme composante des médias acoustiques sous-marins, menant à une réorganisation matérielle du champ acoustique de l’océan.
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Rimsky-Korsakov, N. A., S. A. Sviridov, Yu S. Russak, A. B. Kostin, and N. F. Tikhonova. "DEVELOPMENT AND OPERATION OF DEEP-SEA OCEANOGRAPHIC COMPLEX AS PART OF TOWED VEHICLES “ZVUK”." Journal of Oceanological Research, April 10, 2023, 133–61. http://dx.doi.org/10.29006/1564-2291.jor-2023.51(1).7.
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The article presents a technical review on the development of deep-sea complex with a working depth of immersion and towing of 6000 m in the 1980s at the Shirshov Institute of Oceanology of the USSR Academy of Sciences. The complex was devoted to studies of the bottom surface and underwater objects in the interests of the Hydrographic Service of the Russian Navy. The complex consists of two towed uninhabited underwater vehicles “Sound-Complex” and “SoundMAFT”. A special hydrographic vessel with a displacement of 2600 tons was converted for deep-sea towing and storage of these devices. Computer CM1420 was used for the ship’s automated system for collecting and processing information coming from an underwater hydro acoustic navigation system, a proton magnetometer, a TV system, and side and frontal sonars. The complex was operated until 1992 in the Atlantic Ocean, the Black, Mediterranean and Baltic Seas, and was decommissioned in the early 1990s. Modern issues of the operation of industrial pipelines require understanding of experience and the creation of towed uninhabited underwater vehicles at a new technological level.
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Watanabe, Shun-ichi, Tadashi Ishikawa, Yusuke Yokota, and Yuto Nakamura. "GARPOS: Analysis Software for the GNSS‐A Seafloor Positioning With Simultaneous Estimation of Sound Speed Structure." Frontiers in Earth Science 8 (November 20, 2020). http://dx.doi.org/10.3389/feart.2020.597532.
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Global Navigation Satellite System–Acoustic ranging combined seafloor geodetic technique (GNSS-A) has extended the geodetic observation network into the ocean. The key issue for analyzing the GNSS-A data is how to correct the effect of sound speed variation in the seawater. We constructed a generalized observation equation and developed a method to directly extract the gradient sound speed structure by introducing appropriate statistical properties in the observation equation, especially the data correlation term. In the proposed scheme, we calculate the posterior probability based on the empirical Bayes approach using the Akaike’s Bayesian Information Criterion for model selection. This approach enabled us to suppress the overfitting of sound speed variables and thus to extract simpler sound speed field and stable seafloor positions from the GNSS-A dataset. The proposed procedure is implemented in the Python-based software “GARPOS” (GNSS-Acoustic Ranging combined POsitioning Solver).
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Tomita, Fumiaki, Motoyuki Kido, Chie Honsho, and Ryo Matsui. "Development of a kinematic GNSS-Acoustic positioning method based on a state-space model." Earth, Planets and Space 71, no. 1 (September 23, 2019). http://dx.doi.org/10.1186/s40623-019-1082-y.
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Abstract GNSS-A (combination of Global Navigation Satellite System and Acoustic ranging) observations have provided important geophysical results, typically based on static GNSS-Acoustic positioning methods. Recently, continuous GNSS-Acoustic observations using a moored buoy have been attempted. Precise kinematic GNSS-Acoustic positioning is essential for these approaches. In this study, we developed a new kinematic GNSS-A positioning method using the extended Kalman filter (EKF). As for the observation model, parameters expressing underwater sound speed structure [nadir total delay (NTD) and underwater delay gradients] are defined in a similar manner to the satellite geodetic positioning. We then investigated the performance of the new method using both the synthetic and observational data. We also investigated the utility of a GNSS-Acoustic array geometry composed of multi-angled transponders for detection of vertical displacements. The synthetic tests successfully demonstrated that (1) the EKF-based GNSS-Acoustic positioning method can resolve the GNSS-Acoustic array displacements, as well as NTDs and underwater delay gradients, more precisely than those estimated by the conventional kinematic positioning methods and (2) precise detection of vertical displacements can be achieved using multi-angled transponders and EKF-based GNSS-Acoustic positioning. Analyses of the observational data also demonstrated superior performance of the EKF-based GNSS-Acoustic positioning method, when assuming a laterally stratified sound speed structure. Further, we found three superior aspects to the EKF-based array positioning method when using observational data: (1) robustness of the solutions when some transponders fail to respond, (2) precise detection for an abrupt vertical displacement, and (3) applicability to real-time positioning when sampling interval of the acoustic ranging is shorter than 30 min. The precision of the detection of abrupt steps, such as those caused by coseismic slips, is ~ 5 cm (1σ) using this method, an improvement on the precision of ~ 10 cm of conventional methods. Using the observational data, the underwater delay gradients and the horizontal array displacements could not be accurately solved even using the new method. This suggests that short-wavelength spatial heterogeneity exists in the actual ocean sound speed structure, which cannot be approximated using a simple horizontally graded sound speed structure.
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Merkens, Karlina, Simone Baumann-Pickering, Morgan A. Ziegenhorn, Jennifer S. Trickey, Ann N. Allen, and Erin M. Oleson. "Characterizing the Long-Term, Wide-Band and Deep-Water Soundscape Off Hawai’i." Frontiers in Marine Science 8 (November 15, 2021). http://dx.doi.org/10.3389/fmars.2021.752231.
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Many animals use sound for communication, navigation, and foraging, particularly in deep water or at night when light is limited, so describing the soundscape is essential for understanding, protecting, and managing these species and their environments. The nearshore deep-water acoustic environment off the coast of Kona, Hawai’i, is not well documented but is expected to be strongly influenced by anthropogenic activities such as fishing, tourism, and other vessel activity. To characterize the deep-water soundscape in this area we used High-frequency Acoustic Recording Packages (HARPs) to record acoustic data year-round at a 200 or 320 kHz sampling rate. We analyzed data spanning more than 10 years (2007-2018) by producing measurements of frequency-specific energy and using a suite of detectors and classifiers for general and specific sound sources. This provided a time series for sounds coming from biological, anthropogenic and physical sources. The soundscape in this location is dominated by signals generated by humans and odontocete cetaceans (mostly delphinids), generally alternating on a diel cycle. During daylight hours the dominant sound sources are vessels and echosounders, with strong signals ranging from 10 Hz to 80 kHz and above, while during the night the clicks from odontocetes dominate the soundscape in mid-to-high frequencies, generally between 10 and 90 kHz. Winter-resident humpback whales are present seasonally and produce calls in lower frequencies (200-2,000 Hz). Overall, seasonal variability is relatively subtle, which is unsurprising given the tropical latitude and deep-water environment. These results, and particularly the inclusion of sounds from frequencies above 2 kHz, represent the first long-term analysis of a marine soundscape in the North Pacific, and the first assessment of the intense, daily presence of manmade noise at this site. The decadal time series allows us to characterize the dynamic nature of this location, and to begin to identify changes in the soundscape over time. This type of analysis facilitates protection of natural resources and effective management of human activities in an ecologically important area.