High-bandwidth acoustic data communication for stand-off identification by autonomous underwater vehicles

Stand-off mine countermeasure (MCM) operations with unmanned systems frequently require user involvement for the interpretation of image data, for classification and identification, and for decision-making during mine disposal. As the transfer of image data usually requires tethering, this leads to cumbersome operating procedures. We have...

Development of a Physical Layer for Adaptive Underwater Acoustic Communications

For underwater acoustic modems to operate in a time-varying environment, in-mission adaptation is desirable. A physical layer has been designed that supports mechanisms for ad-hoc configuration changes based on (in-situ and indirectly obtained) channel and noise conditions. Coded preambles are used to instruct the receiver of a configuration...

On the challenge of underwater acoustic communication at short range

It is a persistent misunderstanding that underwater acoustic communication at short range is always easier than at long range. Same for (quasi) stationary configurations being always easier than dynamic ones. This paper gives examples of high-rate links in very shallow water at several kilometres distance, as well as difficult communication...

Acoustic ranging with communication signals for wireless diver guidance to base

There are situations in which divers need to find their way to an unknown location within acoustic communication range as quickly as possible without broadcasting additional energy besides that of already transmitted acoustic communi cation signals, e.g., for acoustic covertness or saving battery life. For these situations, a prototype of a...

EDA-SALSA: Towards smart adaptive underwater acoustic networking

In this paper, the European Defence Agency (EDA)project SALSA is presented. In SALSA, which stands for Smart Adaptive Long- and Short-range Acoustic network, five European navies have united to create a common protocol stack for adaptive underwater acoustic communication and cognitive underwater networking. Within four years, the SALSA stack...

QoS-enabled underwater acoustic communications

For enabling efficient operation of untethered underwater vehicles, error-free underwater communication of command-and-control and telemetry data is a necessity. In contrast, the communication requirements for the sensor data of these vehicles are often less stringent, i.e., a few bad pixels in a SONAR image might be tolerated. To maximize...

Field experiments with a dual-frequency-band underwater acoustic network

For remote deployment of unmanned/autonomous underwater vehicles that, for reasons of size, power usage and cost, communicate acoustically in relatively high frequency bands, a backbone underwater acoustic network needs to support multiple frequency bands with the communication streams being able to cross over between bands as required. This...

Development and demonstration of a live data streaming capability using an underwater acoustic communication link

Autonomous Underwater Vehicles (AUVs) offer an automated solution for the collection of environmental data underwater. While they provide an effective solution in scenarios where their task is limited to basic sensor data collection, supervisory control by an operator is still needed to make more complicated decisions. Because raw data of camera...

Analysis of underwater acoustic propagation in a harbour environment and its effect on communication

Acoustic underwater communication is an enabler for the use of autonomous underwater vehicles (AUVs). AUVs can operate in acoustically challenging environments, e.g., near offshore platforms and in harbours. To realize robust underwater communication in such environments, the propagation conditions need to be properly understood. In this paper,...

Software-Defined Underwater Acoustic Modems Historical Review and the NILUS Approach

Flexible/adaptive acoustic modems that are reprogrammable/reconfigurable at all layers of the communication stack, either by a user or by means of autonomous decisions, are considered as an important enabler for interoperability and cognitive networking in the underwater domain. In this paper, we review the existing literature on software...

Performance of acoustic communications for AUVs operating in the North Sea

Blind equalization of underwater acoustic channels using implicit higher-order statistics

Validation of simulations of an underwater acoustic communication channel characterized by wind-generated surface waves and bubbles

This paper shows that it is possible to simulate realistic shallow-water acoustic communication channels using available acoustic propagation models. Key factor is the incorporation of realistic time-dependent sea surface conditions, including both waves and bubbles due to wind.

Underwater acoustic communication research at TNO-Past and present

This paper provides an overview of more than 12 years of underwater acoustic communication research at the Sonar Department of TNO The Hague. The research covered both point-to-point links and relay networks, from long-range covert communication to short-range high-data-rate communication, for both civil and military applications. The current...

A discrete-time channel simulator driven by measured scattering functions

In-situ measurements of the scattering function are used to drive a channel simulator developed in the context of underwater acoustic telemetry. Two operation modes of the simulator are evaluated. A replay mode is accomplished by interpolation of measured impulse responses. A second, stochastic mode delivers multiple realizations of a given...