Underwater Surveillance System Research Articles

Precision Aquaculture: A Way Forward for Sustainable Agriculture

The escalating demands for food, fiber, energy, and water due to swift population growth have underscored the necessity for the sustainable utilization of natural resources. The advent of precision farming tools and machinery since the 1990s has markedly enhanced productivity and optimized the employment of inputs in aquaculture. The burgeoning connectivity in rural regions and its improved integration with data from sensor systems, remote sensors, equipment, and smartphones have paved the way for innovative concepts in Digital Aquaculture. Automation is the most effective strategy to manage situations, augment productivity, and reduce manufacturing costs. Biosensors are deployed to control unidentified sensor-based remotely and guided aerial vehicles to apply chemicals or fertilizers while monitoring water quality. A sophisticated aeration system manages the concentration of dissolved oxygen. Another critical aspect is the administration of feeding and automatic biomass estimation. Robotics and automatic feeders are employed in ponds and cages to minimize feed wastage and the Feed Conversion Ratio (FCR), with these tools being dependent on the behaviour of the organisms and the water condition. Post-harvest, farmers acquire information on biomass estimation to attain optimal yield. The most vital element is the automatic monitoring of the health and welfare management of the organism to detect any challenging situations or early signs of anomalies. An underwater surveillance system, a camera-based visual system, collects data on water quality, organism activity, feeding, cage biofouling, and net cleaning. Automation is poised to shape the future of the aquaculture industry to make the nations agriculture sustainable.

A novel deep learning based underwater image de-noising and detecting suspicious object

Exploration of underwater resource play a vital role for nation development. Underwater surveillance systems play a crucial role in security applications, requiring accurate detection of suspicious objects in underwater images. However, the presence of noise, poor visibility, and uneven lighting conditions in underwater environments pose significant challenges for reliable object detection. This work proposes an integrated approach for underwater image de-noising, pre-processing, enhancement, and subsequent suspicious object detection by combining the DnCNN (Deep Convolutional Neural Network), CLAHE (Contrast Limited Adaptive Histogram Equalization), and additional image enhancement techniques. In addition to de-noising and pre-processing, it incorporate various image enhancement techniques to further improve object detection performance. These techniques include color correction, contrast adjustment, and edge enhancement, aiming to enhance the visual characteristics and saliency of suspicious objects in underwater images. To evaluate the effectiveness of proposed approach, this work conducted extensive experiments on an underwater image dataset containing diverse scenes and suspicious objects. The work compares proposed method with existing de-noising, preprocessing, and object detection techniques, analyzing the results using quantitative performance metrics, including precision, recall, and F1 score. The experimental results demonstrate that proposed integrated approach outperforms individual methods and achieves superior detection performance by enhancing the quality of underwater images and improving the visibility of suspicious objects.

Enhancing generalization performance of anomaly detection-based active sonar classifier

It is critical to automatically discriminate between target and clutter in developing future unmanned underwater surveillance systems. However, due to similar physical experiences between target echoes and clutter, active sonar classification remains a challenging problem. Recently, a novel anomaly detection-based active sonar classifier, bi-sphere anomaly detection (BiSAD), was proposed, demonstrating improved generalization performance over conventional supervised learning-based approaches. In the present study, we provide a brief overview of active sonar datasets and the BiSAD. Then, we explore modifications to BiSAD, aiming at further improving its generalization capabilities. Through examination using in situ active data, we validate the efficacy of these modifications, showing superior generalization performance compared to conventional supervised learning-based classifiers and the original BiSAD.

Fabrication and Underwater Testing of a Vector Hydrophone Comprising a Triaxial Piezoelectric Accelerometer and Spherical Hydrophone.

A vector hydrophone is an underwater acoustic sensor that can detect the direction of a sound source. Wide-band characteristics and high sensitivity enhance the performance of underwater surveillance systems in complex environments. A vector hydrophone comprising a triaxial piezoelectric accelerometer and spherical hydrophone was fabricated and tested in the air and underwater. The vector hydrophone was designed to exceed the quantitative figures of merit (i.e., receiving voltage sensitivity and bandwidth) of commercially available hydrophones. Accelerometer performance was enhanced by placing a pair of piezoelectric single crystals on each axis and modifying the seismic mass material. The receiving voltage sensitivity of the omnidirectional hydrophone was approximately -160 dB relative to 1 V/μPa with the amplifier in water; the sensitivity of the accelerometer exceeded 300 mV/g in air and -215 dB relative to 1 V/μPa underwater over the frequency range of interest. The receiving directivity of the vector hydrophone was validated underwater, which confirmed that it could detect the direction of a sound source.

Algorithms of optimal covering of 2D sets with dynamical metrics

The paper deals with the problem of constructing the thinnest covering for a convex set by a set of similar elements. As a distance between two points, we use the shortest time it takes to achieve one point from another, and the boundary of each covering circle is an isochron. Such problems arise in applications, particularly in sonar and underwater surveillance systems. To solve the problems of covering with such circles and balls, we previously proposed algorithms based both on variational principles and geometric methods. The purpose of this article is to construct coverings when the characteristics of the medium change over time. We propose a computational algorithm based on the theory of wave fronts and prove the statement about its properties. Illustrative calculations are performed.

The Study of Selecting a Test Area for Validating the Proposal Specification of InSAS(Interferometric Synthetic Aperture Sonar)

This paper provides a case study of development testing and evaluation of design goal of Interferometric SAS (Synthetic Aperture Sonar) system that is developing supported by Civil-Military Technology Cooperation Center in offshore fields. For Deep water operating capabilities evaluation, We have surveyed candidate field, bathymetric mapping and target identification over 200 m depth, East Sea. In testing phase, We have provided environmental information of testing field include water column, seabed and weather condition in real time. And to compare excellency of developing InSAS, we have gather commercial imaging sonar system data with same target. This case study will support the Test Readiness Review of future underwater surveillance system developing via investigate marine testing field environment, testing facilities and planning.

Surveillance Simulator for Undersea Aquaculture Monitoring

This paper deals with simulator development for an underwater aquaculture surveillance system. The aim is to prevent the intrusion of objects into the water. The simulator checks the performance of the alarm system prior to installation in the underwater surveillance system. The simulator tests virtual environments, but reliable experimental results are obtained using two different methods. First, the state space underwater intruder dynamic models is expressed to control several variables at once. Second, the sensor model is designed using a statistical approach, because detection performance decreases for a various reason when detecting objects using the sensor. This simulator uses Matlab GUI as a tool. Setting various test environments (i.e., sensor configuration and sensor detection range) allows the user to analyze the performance of the underwater surveillance system.

The case for an Urban Ocean Observatory

Over the last 16 years the authors have been developing a distributed multi-static active sonar system for port underwater surveillance. Our continuing mission is to develop a robust capability that classifies and tracks the smallest possible objects found in a harbor. We are essentially trying to simultaneously image the entire operational space, and indeed the solution is looking less like a sonar system and more like an imaging system. Developing such a system is a process of continuous optimization, including compensating for the highly time and space variable harbor ocean. Advancement requires greater and greater accuracy and resolution in our environmental measurements and modeling. We envision the system itself becoming a tomographic tool for determining and predicting the ocean state. Here, we make the case for establishing an Urban Ocean Observatory to achieve more rapid and long term progress. Such a laboratory would allow us to efficiently integrate into one test bed, the often stove-piped technologies developed by the underwater acoustic and oceanographic communities. We can study the long term effects of underwater surveillance systems on marine life. The Urban Ocean Observatory can also act as a scale model and speed advancement towards similar littoral and deep water solutions.

Design of Inshore Water Monitoring System Based on IOT

In recent years, countries around the world have deployed a large number of advanced unmanned submersibles in the deep sea to build a complete underwater surveillance system. For the effective detection of threat from underwater, underwater should build three-dimensional multi-dimensional early warning detection system, the development potential of new communication technologies right. This paper designed an offshore environmental monitoring systems. The system includes two subsystems, which waters the information detection subsystem enables real-time monitoring of water information, data distribution subsystem monitoring data can be sent to the specified users through the default network.The system is deployed to the port and nearby offshore waters can achieve anti-submarine reconnaissance information network set up, the next step with advanced acoustic detector can play an important role in the anti-war underwater unmanned underwater vehicles..

부이형 수중감시 시스템에서 계류라인의 구조 설계

부이형 수중감시 시스템은 필요시 특정해역에 설치되어 일정기간 운용하고 회수이후, 다른 해역으로 이동하여 수중감시를 수행하는 장비이다. 본 논문에서는 부이형 수중감시 시스템에 적용되는 계류라인에 대하여 설치성을 유지하고 안정적인 운용이 가능하도록 계류방법을 선정하고 계류라인의 구조를 설계하였다. 부이형 수중감시 시스템의 구성요소인 배열센서조립체의 신호전송 케이블의 간섭을 고려하여 2점 계류방법을 선정하였고, 계류라인은 해역 이동에 따른 설치/회수성을 고려하여 부이체인, 나일론 로프, 그리고 앵커체인의 3단 복합구조를 기본 구성으로 설계하였다. 설계 유효성을 검증하기 위하여 수치실험과 조파수조 시험을 수행하여 유사성을 확인하였으며, 최종적으로 해상시험 위치의 환경을 대상으로 계류라인의 설계를 수행하였다. 최종 설계에 의해 제작된 계류라인은 해상시험을 통하여 설계 시 고려한 유의파고 이상에서도 안정적인 계류를 수행함을 확인하였다.

Geometric Approach to Passive Ranging in Underwater Localization Systems

The use of underwater surveillance systems is critical for effective command of maritime power. Ships or submarines equipped with active sonar systems emit sounds to obtain range or angle information. Unfortunately, security issues may occur in this situation. To meet the security considerations for obtaining location information, a passive tracking or localization technique, the bearings-only target motion analysis (BO-TMA), was developed along with a given direction of arrival (DOA) estimation. With limited resources, a passive ranging approach with only a single passive array is practical, and is considered in this paper. In this paper, we propose a new geometric approach and derive a closed-form solution, which can be implemented in BO-TMA algorithms for initiation and updating the range of targets with a single passive sensor. Finally, analysis and simulation results showed that the proposed scheme can achieve good performance and is effective for a short operation time, such that an observer can move with more flexibility in combat scenarios. The proposed algorithm can further be performed by trackers to generate the initiation information and hence reduce the estimation bias.

A study on the development of the OMS/MP based on the Fundamentals of Systems Engineering

The Systems Engineering method is increasingly recognized as a central in the Acquisition of Weapon Systems in South Korea. Because of these trends, issues concerned with improving weapon system design are increasingly raised. This paper presents a development of Operational Mode Summary/Mission Profile (OMS/MP) in terms of Weapon Systems Acquisition for application to Systems Engineering method. For a systematic approach, a precise concept of OMS/MP is derived by analyzing the concept of conventional OMS/MP. This paper reviews the results of a series of previously reported examples aiming to develop the OMS/MP of a weapon system. Based on this, the limitations of the conventional OSM/MP applications are investigated. And these limitations can be resolved by the Fundamentals of Systems Engineering. Finally, the OMS/MP framework based on the Fundamentals of Systems Engineering has been proposed and is successfully implemented for the Harbor Underwater Surveillance System.

DPSO 알고리즘을 적용한 수동탐지소나 배치 연구

은밀하게 침투하여 아군의 핵심자산으로 접근하는 표적 잠수함을 상시 감시하기 위하여 수중 해저면 위치에 최적의 고정형 수동탐지소나를 배치하는 것을 고려 할 수 있다. 수동탐지소나 배치 최적화를 위한 효과도 지수는 넓은 탐지영역과 위치추정가능성의 함수로 적용할 수 있는데 계절적인 요인, 해상상태, 표적 잠수함의 침투심도 등의 다양한 확률적 변이를 포함하고 있어서 효과도지수가 배치의 입력에 대하여 확률적으로 나타나는 특성을 갖는다. 본 논문에서는 다양한 파라메타의 입력조건에 대하여 확률적인 출력을 갖는 수동탐지소나의 배치에 대한 최적화 문제를 정의하였으며, DPSO(Discrete binary version of PSO) 방법을 사용하여 최적 배치 안을 도출하기 위한 모의기반의 절차를 제시하고 고찰하였다. An arrangement of passive sonars is considered to be a fixed underwater surveillance system for detecting an anti-submarine consistently. An effectiveness score for optimizing the arrangement of passive sonars is defined in a function of the probability of detection and localization. These two features contain various probabilistic variations including seasons, sea states, depths of water, etc. Due to this reason, the effectiveness scores show probabilistic characteristics from the input of the arrangement of passive sonars. This paper defines the optimization problem having the results of probabilistic characteristics from various parameters of input conditions. Also, we suggest a simulation-based process of deciding the optimized arrangement of passive sonars using DPSO(Discrete binary version of PSO) method.

EM-Based High Speed Wireless Sensor Networks for Underwater Surveillance and Target Tracking

Underwater Wireless Sensor Networks (UWSNs) are considered as tangible, low cost solution for underwater surveillance and exploration. Existing acoustic wave-based UWSN systems fail to meet the growing demand for fast data rates required in military operations, oil/gas exploration, and oceanographic data collection. Electromagnetic (EM) wave-based communication systems, on the other hand, have great potential for providing high speed data rates in such scenarios. This paper will(1)discuss the challenges faced in the utilization of EM waves for the design of tactical underwater surveillance systems and(2)evaluate several EM wave-based three-dimensional (3D) UWSN architectures differing in topologies and/or operation principles on the performance of localization and target tracking. To the best of our knowledge, this is the first of its kind in the field of underwater communications where underwater surveillance techniques for EM wave-based high speed UWSNs have been investigated. Thus, this will be a major step towards achieving future high speed UWSNs.

Application of a Winch-type Towed Acoustic Sensor to a Wave-powered Unmanned Surface Vehicle

Although many countries have focused on anti-submarine warfare for several decades, underwater submarines can hardly be detected by current assets such as patrol aircraft, surface ships and fixed underwater surveillance systems. Due to the difficult conditions of the oceanic environment and the relative quietness of submarines, existing acoustic surveillance platforms are not able to fully cover their mission areas. To fill in the gaps, a winch-type towed acoustic sensor system was developed and integrated into a wave-powered unmanned surface vehicle by the Korea Institute of Ocean Science and Technology. In June 2015, sea trial tests were conducted to verify maneuvering, acoustic signal detection, and communication capabilities. During the maneuvering test, the wave-powered glider successfully moved along programmed waypoints. Despite towing the acoustic sensor system, only 20% of initial electricity was consumed in 20 days. The acoustic sensor was lowered to depths of 100–150 m by the winch system, and received signals from an acoustic simulator lowered to depths of 50–100 m by RV Jangmok. Simulated submarine noises that were refracted downward could be clearly received and classified by the hydrophone system, from distances of 2–8 km, while it was being towed silently and deeply. In addition, an optical camera provided high-resolution images of surface vessels, allowing integration with acoustic detection of underwater objects. In conclusion, this new platform using a deeply towed hydrophone system is worthy of consideration as an underwater surveillance asset. Future work is required to strengthen inter-asset communication and obstacle avoidance, and to overcome strong currents to make this technology a reliable part of the underwater surveillance network.

항만 감시를 위한 수중 강자성 표적 탐지에 관한 연구

Many countries have been developing and operating an underwater surveillance system in order to protect their oceanic environment from infiltrating hostile marine forces which intend to lay mines, conduct reconnaissance and destroy friendly ships anchored at the harbor. One of the most efficient methods to detect unidentified submarine approaching harbor is sensing variation of magnetism of target by magnetic sensors. This measurement system has an advantage of high possibility of detection and low probability of false alarm, compared to acoustic sensors, although it has relatively decreased detection range. The contents of this paper mainly cover the analysis of possible effectiveness of magnetic sensors. First of all, environmental characteristics of surveillance area and magnetic information of simulated targets has been analyzed. Subsequently, a signal processing method of separating target from geomagnetic field and methods of estimating target location has been proposed.

다중상태 소나시스템을 적용한 표적반향음 연구 - Part I : 측정시스템 설계

The target echoes contain information on the target such as the orientation, kinematics, and internal structure, as well as the external geometrical shape of the target. In addition, the pattern of the target echoes depends on the arrangement of the transmitters and receivers in space. Therefore, the study of the target echoes in a multi-static SONAR system can be useful for detecting and tracking submerged objects using an underwater surveillance system. For this purpose, an acoustic measuring system for multi-static target echoes was designed and tested in an acoustic water tank. Some preliminary data are presented and discussed.

Network Survivability Performance Evaluation in Underwater Surveillance System Using Markov Model

Underwater Wireless Sensor Network (UWSN) is a useful technology that can be used in Underwater Surveillance System (USS). USSs are mostly used in military purposes for detecting underwater military activities. One of the most important issues in USS is mission reliability or survivability. Due to harsh underwater environment and mission critical nature of military applications, it is important to measure survivability of USS. Underwater sensor node failures can be detrimental for USS. To improve survivability in USS, we propose a fault-tolerant underwater sensor node model. To the best of our knowledge, this is the first fault-tolerant underwater sensor node model in USS that evaluates survivability of an USS. Â We develop Markov models for characterizing USS survivability and MTTF (Mean Time to Failure) to facilitate USS. Performance evaluation results show the effectiveness of proposed model.

Algorithm for Imaging Sonar Target Detection based on Geometry Characteristic and SVM

The attack from small speedboat and underwater robot is becoming more and more serious. And most powerful countries have installed underwater surveillance systems to protect port, ship, seashore depository and anchorage. The detection technology of underwater target is the most important technology in the process of surveillance. In order to take good advantage of the target’s geometry characteristic and classification function of SVM(Support Vector Machine), an algorithm for imaging sonar target detection based on geometry characteristic and SVM is proposed in the paper. The experiment results are presented and show that this algorithm is in high detection rate under complex underwater circumstance.

Theoretical and experimental study of a signal feature extraction algorithm for measuring propeller acceleration in a port surveillance system

Classification and identification of moving vessels by extracting particular features of the underwater radiated noise generated by the propellers for use within a port area are an attractive topic for a port underwater surveillance system. The authors first present a chirp-periodic signal model for the envelope of accelerating propeller noise, then derive the maximum-likelihood estimator (MLE) for the evaluation of acceleration and finally propose a novel algorithm for the extraction of acceleration feature on modulated noise (EAFOMN) of the propellers. In addition, a series of experiments were performed for an accelerating propeller in a large cavitation tunnel. The results of the tests show that the actual signal features of accelerating propeller noise is consistent with the presented theoretical analysis, and the proposed algorithm is efficient for passively extracting acceleration of propeller rotation speed.