05-11-2012, 05:13 PM
UNDER WATER WIRELESS COMMUNICATION
Abstract
Underwater communication is a technique of sending and receiving message below water. There are several ways of employing such communication but the most common is using hydrophones. Underwater communication has a range of applications including Remotely Operated Vehicle (ROV) and Autonomous Underwater Vehicle (AUV) communication and docking in the offshore industry. Current underwater transmission techniques are primarily utilizing sound waves for large distance at lower frequencies.
The use of electromagnetic (EM) techniques underwater has largely been overlooked because of the attenuation due to the conductivity of seawater. However, for short range applications, the higher frequencies and much higher velocity can prove advantageous.The signals that are used to carry digital information through an underwater channel are acoustic waves which can propagate over long distances. The three distinguishing characteristics of this channel are frequency-dependent propagation loss, severe multipath and low speed of sound propagation.
Keywords: Remotely Operated Vehicle (ROV), Autonomous Underwater Vehicle (AUV), Electro Magnetic (EM) techniques, Acoustic waves.