Helicopter Long-Range Active Sonar DS-100

The Helicopter Long-Range Active Sonar (HELRAS) DS-100 is the highest performance helicopter dipping sonar in the world, according to its manufacturer.

The wet end consists of a descending vertical transmit array of seven projector elements and a receive array of eight hydraulically driven arms which expand to a diameter of 8 ft 6 in (2.6 m) when deployed.

The sonar is capable of operating at depths to 1,600 ft (500 m) and has figure of merit (FOM) sufficient to achieve second...