A Compact Acoustic Communication Module for Remote Control Underwater

This paper describes an end-to-end compact acoustic communication system designed for easy integration into remotely controlled underwater operations. The system supports up to 2048 commands that are encoded as 16 bit words. We present the design, hardware, and supporting algorithms for this system. A pulse-based FSK modulation scheme is presented, along with a method of demodulation requiring minimal processing power that leverages the Goertzel algorithm and dynamic peak detection. We packaged the system together with an intuitive user interface for remotely controlling an autonomous underwater vehicle. We evaluated this system in the pool and in the open ocean. We present the communication data collected during experiments using the system to control an underwater robot.National Science Foundation (U.S.) (NSF 1117178)National Science Foundation (U.S.) (NSF IIS1226883)National Science Foundation (U.S.) (Award 112237

The Hierarchic treatment of marine ecological information from spatial networks of benthic platforms

Measuring biodiversity simultaneously in different locations, at different temporal scales, and over wide spatial scales is of strategic importance for the improvement of our understanding of the functioning of marine ecosystems and for the conservation of their biodiversity. Monitoring networks of cabled observatories, along with other docked autonomous systems (e.g., Remotely Operated Vehicles [ROVs], Autonomous Underwater Vehicles [AUVs], and crawlers), are being conceived and established at a spatial scale capable of tracking energy fluxes across benthic and pelagic compartments, as well as across geographic ecotones. At the same time, optoacoustic imaging is sustaining an unprecedented expansion in marine ecological monitoring, enabling the acquisition of new biological and environmental data at an appropriate spatiotemporal scale. At this stage, one of the main problems for an effective application of these technologies is the processing, storage, and treatment of the acquired complex ecological information. Here, we provide a conceptual overview on the technological developments in the multiparametric generation, storage, and automated hierarchic treatment of biological and environmental information required to capture the spatiotemporal complexity of a marine ecosystem. In doing so, we present a pipeline of ecological data acquisition and processing in different steps and prone to automation. We also give an example of population biomass, community richness and biodiversity data computation (as indicators for ecosystem functionality) with an Internet Operated Vehicle (a mobile crawler). Finally, we discuss the software requirements for that automated data processing at the level of cyber-infrastructures with sensor calibration and control, data banking, and ingestion into large data portals.Peer ReviewedPostprint (published version

Cost-Effective and Energy-Efficient Techniques for Underwater Acoustic Communication Modems

Finally, the modem developed has been tested experimentally in laboratory (aquatic environment) showing that can communicates at different data rates (100..1200 bps) compared to state-of-the-art research modems. The software used include LabVIEW, MATLAB, Simulink, and Multisim (to test the electronic circuit built) has been employed.Underwater wireless sensor networks (UWSNs) are widely used in many applications related to ecosystem monitoring, and many more fields. Due to the absorption of electromagnetic waves in water and line-of-sight communication of optical waves, acoustic waves are the most suitable medium of communication in underwater environments. Underwater acoustic modem (UAM) is responsible for the transmission and reception of acoustic signals in an aquatic channel. Commercial modems may communicate at longer distances with reliability, but they are expensive and less power efficient. Research modems are designed by using a digital-signal-processor (DSP is expensive) and field-programmable-gate-array (FPGA is high power consuming device). In addition to, the use of a microcontroller is also a common practice (which is less expensive) but provides limited computational power. Hence, there is a need for a cost-effective and energy-efficient UAM to be used in budget limited applications. In this thesis different objectives are proposed. First, to identify the limitations of state-of-the-art commercial and research UAMs through a comprehensive survey. The second contribution has been the design of a low-cost acoustic modem for short-range underwater communications by using a single board computer (Raspberry-Pi), and a microcontroller (Atmega328P). The modulator, demodulator and amplifiers are designed with discrete components to reduce the overall cost. The third contribution is to design a web based underwater acoustic communication testbed along with a simulation platform (with underwater channel and sound propagation models), for testing modems. The fourth contribution is to integrate in a single module two important modules present in UAMs: the PSK modulator and the power amplifier

Advanced Engineering Laboratory project summaries 1994

The Advanced Engineering Laboratory of the Woods Hole Oceanographic Institution is a development laboratory within the Applied Ocean Physics and Engineering Department. Its function is the development of oceanographic instrumentation to test developing theories in oceanography and to enhance current research projects in other disciplines within the community. This report summarizes recent and ongoing projects performed by members of this laboratory

Advanced Engineering Lab project summaries 1991

The Advanced Engineering Laboratory of the Woods Hole Oceanographic Institution is a development laboratory within the Applied Ocean Physics and Engineering Department. Its function is the development of oceanographic instrumentation to test developing theories in oceanography, and to enhance current research projects in other disciplines within the community. This report summarizes recent and ongoing projects performed by members of this laboratory

A TESTBED DESIGN FOR MONITORING THE LONG-TERM SPATIAL-TEMPORAL DYNAMICS OF UNDERWATER ACOUSTIC CHANNELS

The underwater acoustic network testbed helps to validate the theoretical results and bridge the gap between experimental results. Characterizing and modeling the spatial-temporal dynamics of underwater acoustic channels is essential to developing efficient and effective physical-layer communication algorithms and network protocols. This work dedicates to designing a testbed system to measure the spatial-temporal dynamics of underwater acoustic channels. The collected measurements will shed insights into the spatial-temporal correlation of underwater acoustic channels and will be used to evaluate the theoretical algorithms that are designed to model the spatial-temporal dynamics and to exploit the spatial-temporal dynamics for more efficient and effective underwater system operations. The report speaks about how to tackle the above problem and discusses the following aspects in detail which are, individual node design which is controlled by a raspberry pi, comparison of the current test bed with the existing testbeds in field, complete description of the server algorithm and its error handling techniques, development of the server level GUI and web-based GUI and finally some of the experimentations carried out in Portage lake and Keweenaw bay

Mobile underwater sensor networks for protection and security: field experience at the UAN11 experiment

An underwater acoustic network (UAN) represents a communication infrastructure that canoffer the necessary flexibility for continuous monitoring and surveillance of critical infras-tructures located by the sea. Given the current limitation of acoustic-based communicationmethods, a robust implementation of UANs is still an open research field. The FP7 UANproject addressed such a problem, and it reached the integration of a mobile underwatersensor network within a wide-area network, which included above water and underwatersensors, for protection and security. This paper describes some of the main results achievedduring the project. In particular, this work addresses solutions for the upper-layers of theUAN, with focus on the integration of autonomous underwater vehicles (AUVs) as mobilenodes of the network, and on the inclusion of network security mechanisms. The recent at-sea successes that have been demonstrated within the UAN framework are detailed. Resultsare given of the final UAN project demonstration, UAN11, held in the May of 2011, whenan underwater acoustic network composed by four fixed nodes, two autonomous underwa-ter vehicles (AUVs), and one mobile node mounted on the supporting research vessel, wascontinuously operated for one week, and integrated into a global protection system

Modular Autonomous Biosampler (MAB)- A prototype system for distinct biological size-class sampling and preservation

Presently, there is a community wide deficiency in our ability to collect and preserve multiple size-class biologic samples across a broad spectrum of oceanographic platforms (e.g. AUVs, ROVs, and Ocean Observing System Nodes). This is particularly surprising in comparison to the level of instrumentation that now exists for acquiring physical and geophysical data (e.g. side-scan sonar, current profiles etc.), from these same platforms. We present our effort to develop a low-cost, high sample capacity modular,autonomous biological sampling device (MAB). The unit is designed for filtering and preserving 3 distinct biological size-classes (including bacteria), and is deployable in any aquatic setting from a variety of platform modalities (AUV, ROV, or mooring)