SONOBUOY

Having earned this reputation over a fifty-year period of success at designing and producing products for critical applications in extreme marine environments, USSG is the world's largest manufacturer of sonobuoys.

As a supplier of ASW products, USSG has designed, developed and manufactured hydrophones for passive and active omnidirectional and directional sonobuoys.

In response to the ever quietening of today's modern submarines, Hermes Electronics developed the AN/SSQ-53D2 DIFAR.

During 1940, German submarines operating in 'Wolf Packs' were attacking Allied convoys supplying Great Britain. Their mode of operation was to close in on the inadequately defended convoys from astern and carry out co-ordinated torpedo attacks. At first the human eye was the primary means of detecting these submarines. Later radar was installed on aircraft, but it could only detect submarines operating on the surface.
USSG also produces towed arrays for use in Ultra's Surface Ship Torpedo Defence solution for the Royal Navy.

Ultra Electronics legacy in torpedo defence was rewarded in 2002 when it was selected to be the Surface Ship Torpedo Defence provider for the Royal Navy.

The company also manufactures a number of different active transducers for high power underwater acoustics applications.

Underwater acoustics distributed surveillance systems are networks of sensors that can be spread over large ocean regions to provide information about the locations of submarines and surface combatants.

The Resonant Pipe Projector RPP is a high power, very low frequency underwater acoustics source designed for moored applications.

Low Frequency Active sonobuoys, Multi Static receivers, and Deployed Autonomous Sensor Systems are but a few of the areas in which Ultra Electronics is investigating in order to field the next...

Horizontal Projector Array HPA
The Horizontal Projector Array HPA is a non-traditional approach to low frequency active LFA sonar that has been the subject of active research and development in Canada.

Low Frequency Projectors
To meet the need for low-frequency towed active sonar, UnderSea Sensor Systems Group manufactures a line of low-frequency acoustic projectors.

The transmit array and receive arrays are contollable via satellite down link and the entire system will be utilised to provide a multi-static sonar capability.

Having earned this reputation over a fifty-year period of success at designing and producing products for critical applications in extreme marine environments, USSG is the world's largest manufacturer of sonobuoys.

As a supplier of ASW products, USSG has designed, developed and manufactured hydrophones for passive and active omnidirectional and directional sonobuoys.

USSI and Maritime Systems are wholly owned by Ultra Electronics Holdings plc, UK. Ultra is an internationally based group of businesses specializing in Aerospace and Defense electronic niche markets worldwide.

Manufacturing Capability Approximately 175,000 square feet of facility space are dedicated to Ultra Electronics'

To date more than three million sonobuoys have been produced for military customers that span the globe. In addition, USSG is involved in other aspects of undersea warfare including towed arrays, surface ship torpedo defence systems, autonomous underwater surveillance systems, mine countermeasures, and towed low-frequency sonar.

Maritime Systems operates Canada's largest towed array manufacturing facility and supports the Canadian Victoria Class submarines and City Class frigates as well as the Royal Navy's Surface Ship Torpedo Defence program.


The Sonar Research Projector SRP System was developed by USSG from COTS commercial-off-the-shelf components to support on-going research into active and passive sonar systems for Defence Science and Technology Organisation DSTO of Australia.

The AN/SSQ-53F is the latest generation passive sonobuoy in production for the US Navy. Combining the functionality of a calibrated omni sensor with that of the AN/SSQ-53E DIFAR, this sonobuoy replaces both the AN/SSQ-57 and the AN/SSQ-53.

Current passive hydrophone ship technology is widely touted as the industry's best being employed in product used by the US, UK, and Canada. Active transducers are designed to be efficient and robust as well as offering a wide bandwidth of operation.

Currently designed for fitment on a variety of warships from fast patrol boat to large carriers, Ultra is investigating similar ship technology for use by submarines.


Over the years since these beginnings, the UnderSea Sensor Systems Group has been at the forefront of sonobuoy development and manufacturing. To date, the Group has manufactured over six million sonobuoys, more than any other organization anywhere, and we are busy manufacturing more, both active and passive sonobuoy types, for both North American users as well as the international markets.

As a consequence, the British realized that a remote device located in the water was needed to detect hostile submarines as they approached.

Maritime Systems operates Canada's largest towed array manufacturing facility and supports the Canadian Victoria Class submarines and City Class frigates as well as the Royal Navy's Surface Ship Torpedo Defence program

his complex system composed of a high powered low frequency sound source in conjunction with a number of volumetric receive arrays will be deployed from the
All of the sensor data is digitized and brought into the processor.

Acoustic data and non-acoustic data are processed separately, examining the received energy for target-of-interest characteristics.

Low Frequency Active sonar used either monostatically or as a multi static source can offer significant improvements in submarine detection ranges. UnderSea Sensor Systems Group has supplied towed sonar systems using a variety of different transducer technologies to a number of clients.

To meet the need for low-frequency towed active sonar, UnderSea Sensor Systems Group manufactures a line of low-frequency acoustic projectors.

Ocean Systems based in Weymouth, UK and Hermes based in Nova Scotia, Canada, are combining their specialist expertise in the design, development, and manufacture of the complete sonar system.

The FFR projector is a high power, low frequency, broad bandwidth, and high efficiency sonar transducer designed for operation above approximately 1 kHz.

Over the years since these beginnings, the UnderSea Sensor Systems Group has been at the forefront of sonobuoy development and manufacturing. To date, the Group has manufactured over six million sonobuoys, more than any other organization anywhere, and we are busy manufacturing more, both active and passive sonobuoy types, for both North American users as well as the international markets.

Ultra Electronics started to produce sonobuoys in small numbers, in the later 1940s, using a Ministry of Aviation design.

At the same time Ultra Electronics in the UK began work on the T9003 directional passive sonobuoy, which rotated mechanically at about 3 rpm, together with its companion the T11514 directional active sonobuoy.

Current towed array activities has centered on a high dynamic range, fully digital replacement for the SQR-19 employed on Canadian frigates as well as to and serve as the passive sensor on an Integrated Active Passive Sonar System. USSG also produces towed arrays for use in Ultra's Surface Ship Torpedo Defence solution for the Royal Navy.

Current towed array activities has centered on a high dynamic range, fully digital replacement for the SQR-19 employed on Canadian frigates as well as to and serve as the passive sensor on an Integrated Active Passive Sonar System.

USSI formerly the Magnavox / Hughes Company's sonobuoy division has a well-deserved reputation as an innovative provider of sonar algorithms, surveillance systems, and digital signal processing to the United States Navy.

Extensive use of commercial digital ship technology coupled with Hermes' volume production facility has produced one of the world's most cost effective solutions for an SSTD array.

In addition to the use of Globalstar satellite communications, the system will also employ wideband spread-spectrum terrestrial communications ship technology.


Replacing the obsolete AN/SSQ-47B Range-Only ‘pinger’, the AN/SSQ-62 DIrectional Command Activated sonobuoy System (DICASS) is recognised as the primary active sonobuoy in service today. DICASS permits the operator to pinpoint a target’s position in range and bearing from the sonobuoy in contact.

This 266 meter, 64 acoustic channel array has been modified to interface with the Sonar 2046 found on Canada's new Victoria Class submarines.

Underwater distributed surveillance systems are networks of sensors that can be spread over large ocean regions to provide information about the locations of submarines and surface combatants.


The proposed solution was to drop floating canisters equipped with hydrophones from the stern of the surface ships.

Acoustic and non-acoustic data are combined fused and compared to make a final determination of the presence of targets and the target's location and track.

Any targets have the appropriate data formatted into a contact report which is sent via the underwater acoustics communications to other nodes and via the gateway buoy to the user.
Maritime Systems is renowned in its capability to design and manufacture military towed arrays and low frequency sonar.

In the early 1960s the Low Frequency Analysis and Recording LOFAR technology was developed in the USA. The first LOFAR production sonobuoy, the AN/SSQ-41 was fielded in 1965 as an omnidirectional passive, 'A'-size sonobuoy 36 inches long by 4.875 inches diameter.

UnderSea Sensor Systems' experience with sonobuoys, oceanographic sensors and sonar transducers has led to the successful development and production of the first commercially marketed Barrel Stave Projector BSP.

The Sonar Research Projector SRP System was developed by USSG from COTS commercial-off-the-shelf components to support on-going research into active and passive sonar systems for Defence Science and Technology Organisation DSTO of Australia.


Replacing the obsolete AN/SSQ-47B Range-Only ‘pinger’, the AN/SSQ-62 DIrectional Command Activated sonobuoy System (DICASS) is recognised as the primary active sonobuoy in service today. DICASS permits the operator to pinpoint a target’s position in range and bearing from the sonobuoy in contact.

Ultra Electronics three sonobuoy companies - Sonar and Communication Systems UK, UnderSea Sensor Systems Inc. US and Maritime Systems Canada currently offer the customer a full range of production sonobuoys.

Ultra Electronics legacy in torpedo defence was rewarded in 2002 when it was selected to be the Surface Ship Torpedo Defence provider for the Royal Navy.

Ultra Electronics legacy in torpedo defence was rewarded in 2002 when it was selected to be the Surface Ship Torpedo Defence provider for the Royal Navy. The System which is used to detect and localise incoming threat torpedoes not only provides the means to decoy or jam the homing mechanism of the torpedo, but it is also capable of offering tactical advice to the ship's Captain.

Hermes' Surface Ship Torpedo Defence SSTD array is a high frequency passive digital array with an extended acoustic intercept capability.

Maritime Systems is renowned in its capability to design and manufacture military towed arrays and low frequency passive sonar.

This 266 meter, 64 acoustic channel array has been modified to interface with the Sonar 2046 found on Canada's new Victoria Class submarines.

USSI is responsible for the implementation of the undersea portion of the DADS system including intergration of a variety of acoustic and non-acoustic ship technology as well as in-sensor processing.