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Sonobuoys
A true leader in the design and manufacture of air-launched acoustic sensor systems, Maritime Systems has produced and delivered more than two million sonobuoys. In concert with its sister division Sonar and Communications Systems in the UK, Maritime Systems is also able to offer its customers a complete range of environmental, passive, active, and multi-static sonobouys.
Bathythermal Sonobuoys
Ultra's bathythermal sonobuoys are available in both A and G size variants. A bathythermal buoy relays, by VHF FM radio transmissions, water temperature profile information measured by a constant velocity, descending probe. The information provided by a bathythermal buoy allows the antisubmarine operator to understand the underwater acoustic environment and predict where a submarine is likely operating. This knowledge helps the ASW operator to deploy sonobuoys for detection of underwater targets.
Available products:
AN/SSQ-36B 
AN/SSQ-536G
AN/SSQ-937D
Passive Sonobuoys
Passive sonobuoys support the covert detection, classification, localization and attack of a submarine through the detection of the narrowband, broadband and transient sounds that are emitted from even the quietest, modern submarine. Passive sonobuoys can also be used as the receiver elements of a multi-static acoustic search system. Passive sonobuoys include point receivers such as LOFAR and DIFAR, vertical line arrays like the VLAD, and horizontal planar arrays exemplified by the Barra.
Passive Sonobuoys
The LOFAR sonobuoy is used for passive detection and tracking of sub-surface targets of interest. This low cost sonobuoy is currently manufactured in G size form factor permitting it to be carried on helicopters and small Maritime Patrol Aircraft.
Available products:
AN/SSQ-906G
Directional Sonobuoys
The DIFAR is the most widely used sonobuoy by today's ASW operators. Like its precursor, the LOFAR sonobuoy, a DIFAR sonobuoy can be used to provide identification of acoustic information emanating from a submarine or surface ship. This 'acoustic fingerprint' can identify the target as friend or foe, the class of vessel, and in some cases even the vessel's hull number can be determined due to unique acoustic traits. The use of several DIFAR sonobuoys in contact with the target can be used to precisely establish the course and speed of the target. In some cases the depth of the target can also be established using a DIFAR sonobuoy. Where a DIFAR sonobuoy differs from the LOFAR is that it contains a directional sensor, which provides a bearing from the sonobuoy to the target of interest.
Available products:
AN/SSQ-53D(2)
AN/SSQ-53D(3)
AN/SSQ-955
Horizontal Planar Array Sonobuoys
Horizontal Planar Array sonobuoys, such as Barra, offer increased performance for both littoral and deep water operations. These sonobuoys permit broadband passive detection and tracking and narrowband analysis as well as the ability to function as a Multistatic receiver. Far more complex than a standard DIFAR sonobuoy, Barra incorporates adaptive digital signal processing so as to optimise SNR in real-life, non-ideal conditions.
Available products:
AN/SSQ-981E
Active Sonobuoys
Active sonouboys enable an aircraft to rapidly localize and attack a hostile submarine. They are traditionally used to prosecute a submarine detected on non-acoustic sensors or to follow-up an attack mounted using passive sonobuoys.
Active sonobuoys are employed during the attack phase of antisubmarine operations or when the rapid localization of a fleeting contact is necessary such as disappearing radar contact.
Active sonobuoys are overt and cannot be used for target classification. They do provide a range and bearing to the target and can be used to establish the target's course and speed after multiple fixes.
CAMBS Sonobuoys
The Commandable Active Multi-Beam Sonobuoy (CAMBS) active sonobuoy has been in production for over three decades. Because CAMBS has a command link, there exists flexibility in operating this sonobuoy in order to best maintain contact with the sub surface contact of interest over a wide range of environmental and target conditions.
Available products:
AN/SSQ-963D
Multi-Static Active Sonobuoys
The move to littoral operations and the increasing threat from the smaller diesel submarine is tipping the balance back in favour of the submarine. These submarines, especially when able to remain submerged using Air Independent Propulsion (AIP), are much smaller, stealthier, and therefore more dangerous opponents. Multi-statics is one method being advocated to regain much of this lost ASW capability. A multi-static system places the source and multiple receivers in different locations. This allows the problem of dead zones to be overcome giving greater coverage. Ultra Electronics is a world leader in airborne mutli-statics producing both transmit and receive sonobuoys designed specifically for multi-static operation. These sonobuoys are effective not only when deployed from long range maritime patrol maritime patrol aircraft, but also work with ASW helicopters and towed array equipped warships.
Available products:
AN/SSQ-926
AN/SSQ-565
AN/SSQ-981E
AN/SSQ-573