Real time transmission of images and data through underwater acoustic channel the TRIDENT system

Underwater acoustic communication current needs are increasing. Civil and military applications are large. In this context, GESMA (Groupe d'Etudes Sous-Marines de l'Atlantique), initiated the Project TRIDENT (TRansmission d'Images et de Donnees EN Temps reel). Project objective is to develop a high data rate link allowing the transmission of various information (text, images...). A real-time receiver platform, using a Digital Signal Processor (DSP) and based on a spatio-temporal equalizer developed and patented by ENST Bretagne, was carried out to reduce the various perturbations brought by the underwater acoustic channel (UWA). Sea trials, realized in 2002 and 2003, permitted to validate the receiver platform. The different results show the robustness of the TRIDENT system for transmission in a strongly disturbed channel. The TRIDENT system allows data transmissions with a bit data rate ranging from 8 to 25 kbps for distances higher than 2000 meters.