HERMES - A high-speed acoustic modem for real-time transmission of uncompressed image and status transmission in port environment and very shallow water

A new generation of high-speed, high-frequency acoustic modem, named HERMES, has been developed. The acoustic communications link consists of a topside component and an underwater (wet-side) component. Together these components implement two underwater acoustic communication channels: a very high bit rate broadband data uplink and a low bit rate command downlink. The experimental results, obtained with the high-speed high-frequency acoustic uplink, demonstrate the system´s ability to transmit high-resolution, uncompressed acoustic images with sufficient quality for any practical purposes. At the fastest data rate (mode 5), HERMES can transmit an uncompressed, high-resolution 400000-bit sonar image in 4.6 seconds. The results presented in this paper demonstrate that these data can be transmitted at a range of 120 m.