ACME

Acoustic Communication network for Monitoring of underwater Environment in coastal areas
December 2001 - November 2003

Objectives

ACME is a European Project within the Energy, Environment and Sustainable Development Cluster of the 5th Framework Program of the European Commission, focussing on the design of robust communication and protocol algorithms, which will be implemented and tested in a prototype of a shallow water acoustic communication network capable of conveying data from several underwater sensors to a central node in areas where means of communication other than acoustic are prohibited.

Background

Systems capable of monitoring the environment and/or to control equipments on large areas, either in quasi real time or episodically on the request of an end user are used more and more. Such systems comprise of sensors located on the sea floor or in the water whose data has be forwarded to a shore station. These bottom settled underwater devices also have to be remotely controlled from the shore by the end user. Up to now each of these underwater equipments is therefore linked to shore either by cable or via radio network. In this last case, several surface buoys have to be deployed above the underwater sensors. However it is often not possible to set surface buoys and cable on the sea floor because of associated cost, environmental conditions or human activities. In other cases it is even quite impossible to set such cables or surface buoys.

In such conditions, the only way to transfer data from sensors to end user or to remotely control underwater devices from shore is to use an underwater acoustic communication link: acoustic modems (transmitter and/or receiver) are deployed at sea, most of them close to the sensors, to create an acoustic network. Specific protocol and data transmission schemes will allow data to be carried by the network from all points of measurement to a shore station, possibly for further radio dispatching.

However, creating a robust and reliable underwater acoustic communication link (so-called acoustic modem) in a shallow water environment is a complex task. The environment in coastal areas, especially in or near shipping lanes is acoustically extremely difficult. It is characterised by severe multi-path propagation, rapidly changing conditions (e.g. turning of the tide) and high noise levels (e.g. ships). Moreover, the acoustic modems will typically have to be placed near or on the seabed, which will often prevent the existence of a direct sound path between two modems.

The overall objective of the project ACME is to design robust communication and protocol algorithms, which will be implemented and tested in a prototype of a shallow water acoustic communication network that can be deployed in shipping lanes or other coastal areas where data have to be conveyed acoustically. Such a network must be autonomous which poses special demands to robustness. For example, the network must be able to cope with temporally poor communication between nodes and the algorithms must be either self-adaptive or insensitive to changing environmental conditions. Operator intervention will be difficult, if not impossible.

To achieve this objective, ACME has to add new algorithmic developments and ideas to overcome both the specific acoustic conditions and the problems posed by multi-node networking.

Technologies

Partners

Home > CV > Projects
Last update: June 8, 2002
Copyright M.W. Nelisse - All rights reserved.