The Surveillance Towed Array Sensor System (SURTASS)
is a low frequency passive surveillance system that is deployed
on surface ships with acoustic data collection and analysis
capabilities. SURTASS provides passive detection of
quiet nuclear and diesel submarines and real-time reporting
of surveillance information to theater commanders.
The system consists of a long acoustic array, which is towed
by a surface ship and carries environmental sensors, electronic
components, and hydrophones that can detect underwater sound
The Low Frequency Active (LFA) system will be used when
a target is too quiet to be detected by the passive (SURTASS)
LFA is a set of acoustic transmitters suspended by cable beneath
a surface ship. These “projectors” produce an underwater sound
pulse or “ping,” much as a stereo speaker turns electrical impulses
into audible sound waves in the air.
Compact LFA (CFLA)
As future undersea warfare requirements continue to transition to littoral ocean regions, the introduction of a compact active system deployable on SURTASS ships was needed. This system upgrade is known as Compact LFA, or CLFA. CLFA consists of smaller, lighter-weight source elements than the current LFA system, and is compact enough to be installed on the VICTORIOUS class platforms (T-AGOS 19). The operational characteristics of CLFA are comparable to the existing LFA system.The initial CLFA installation was completed on the USNS ABLE (T-AGOS 20) in 2008 and at-sea-testing commenced in August 2008. CLFA improvements include:
- Operational frequency, within the 100 to 500 Hz range, matched to shallow water environments with little loss of detection performance in deep water environments
- Improved reliability and ease of deployment.
- Lighter-weight design with mission weight of 64,410 kilograms (kg) (142,000 pounds [lb]) vice 155,129 kg (324,000 lb) mission weight of LFA).
With the R/V Cory Chouest’s retirement in FY 2008, two systems are currently operational. At present, there is one SURTASS LFA sonar system onboard USNS IMPECCABLE (T-AGOS 23) and one SURTASS CLFA sonar system onboard the USNS ABLE (T-AGOS 20). Two additional CLFA systems are planned for the T-AGOS 19 Class. Late in FY 2011, the CLFA system onboard the USNS EFFECTIVE (T-AGOS 21) commenced at-sea testing and training. The CLFA system to be installed onboard the USNS VICTORIOUS (T-AGOS 19) is scheduled for at-sea testing and training in FY2012.