AN/UQQ-2 Surveillance Towed Array Sensor System

The Navy has spent over $16 million on scientific research on the effects on marine mammals and mitigation systems as well as the development of an Environmental Impact Statement.

[3] SURTASS LFA is a long-range, all-weather, sonar system with both passive and active components, operating in the low frequency (LF) band (100–500 hertz [Hz]).

LFA is a set of acoustic transmitting source elements suspended by cable from underneath a ship.

The characteristics and operating features of LFA are: The passive, or listening, part of the system is SURTASS, which detects returning echoes from submerged objects, such as submarines, through the use of hydrophones.

The SURTASS LFA ship must maintain a minimum speed of approximately 6 kilometres per hour (3.2 knots) through the water in order to tow the hydrophone array in the horizontal plane.

The return signals or echoes, which are usually below background or ambient noise level, are then processed and evaluated to identify and classify potential underwater targets.