Atlas Elektronik GmbH has been commissioned by the Korean yard Daewoo Shipbuilding & Marine Engineering (DSME) with the supply and integration of a bow sonar (ASO) as well as a low-frequency active towed array sonar (ACTAS) for a new frigate of the Royal Thai Navy. Delivery of the systems is planned to take place early in 2016.

Together, the two systems offer active and passive sonars for the detection, tracking and classification of underwater vehicles, such as submarines, torpedoes and unmanned underwater vehicles (UUV). In addition, these sonars are able to detect and classify small speedboats, divers or floating obstacles, e.g. containers or tethered mines.

The ASO bow sonar operates in the frequency range between 6 and 9 kHz and provides a surveillance radius of up to 15 kilometres around the ship. This makes it most suitable for the self-protection of the ship. The towed array sonar ACTAS operates in the low-frequency range from about 2 kHz and permits observation of the sea space at ranges considerably above 60 kilometres, depending on the propagation conditions of the water. This gives the sonar an operational range that by far exceeds that of radars and the weapons range of submarines. The system is therefore not only ideal for hunting submarines but also for the wide-area reconnaissance of surface combatants.

Both sonar systems represent state-ofthe-art from Atlas Elektronik and, besides newly developed signal processing methods, offer a unified hardware design with the corresponding simplifications in servicing and support.