All Products from Sonobuoy TechSystems

Passive Sonobuoys

Localization, or the precise determination of a submarine’s location, course, and speed, is done with passive sonobuoys whenever possible. In the 1980s, when airborne US Navy searched for submarines, passive sonobuoys typically performed the majority of initial detections. Passive tactics are used because they deny a submarine the knowledge that a tracking aircraft is present. The “A” size sonobuoys discussed below can be air-launched since they all employ a parachute to retard their descent and provide descent stability. They can also be hand-launched over the side of a ship. All employ a battery which is energized upon saltwater contact. Once energized, a mechanism for inflating a float with CO2 gas is activated, suspending the sonobuoy. The sensors are then released to specified depths.

Passive sonobuoys use hydrophones to convert underwater sound into electrical signals which are amplified and frequency modulated for VHF transmission. Some sonobuoys have precision-calibrated hydrophones. Most sonobuoys automatically scuttle within 8 hours of deployment. Sonobuoys are typically shipped in a Sonobuoy Launch Container (SLC) that serves as the shipping, storage, and aircraft launch container or in a gray overpack for pneumatic or free-fall launch.

For the DIFAR (Directional Frequency Analysis and Recording) sonobuoys, the main sensor is a hydrophone that has directional detection capabilities. The latest generation of DIFAR sonobuoys offers various sensor types, electronic selection, and post-launch control.

AN/SSQ-53F DIFAR

The AN/SSQ-53F DIFAR is a directional passive sonobuoy no longer being produced for the U.S., but is still available at competitive pricing by removing features from newer model DIFAR sonobuoys. Basic capabilities include four hydrophone depth selections (90, 200, 400, and 1000 feet), five life selections (0.5, 1, 2, 4, and 8 hours), DIFAR, Constant Shallow Omni Sensor (CSO) or a 5 Hz – 20 kHz bandwidth Calibrated Omni (CO) sensor selection capability that is superior to older LOFAR sensors, DIFAR AGC (Automatic Gain Control) On/Off, and the capability to set one VHF transmitter channel out of 96 available channels. Depth, life, sensor, AGC, and channel selection may be set using Electronic Function Selection (EFS) prior to launch and all but depth selection can be changed after deployment via Command Function Select (CFS). RF Power On/Off can also be managed after the sonobuoy is activated. This sonobuoy automatically scuttles after 8 hours.

Download ANSSQ-53F Data Sheet

AN/SSQ-53G DIFAR

The AN/SSQ-53G DIFAR is the latest directional passive sonobuoy with GPS that requires specific CFS commands being produced for most P-8 aircraft. Basic capabilities include four hydrophone depth selections (90, 200, 400, and 1000 feet), five life selections (0.5, 1, 2, 4, and 8 hours), DIFAR, Constant Shallow Omni Sensor (CSO) or Calibrated Omni (CO) sensor selection with 20 kHz or 40 kHz capability, DIFAR AGC (Automatic Gain Control) On/Off, and the capability to set one VHF transmitter channel out of 96 available channels. Depth, life, sensor, AGC, and channel selection may be set using Electronic Function Selection (EFS) prior to launch and all but depth selection can be changed after deployment via Command Function Select (CFS). RF Power On/Off can also be managed after the sonobuoy is activated. This sonobuoy automatically scuttles after 8 hours.

Download AN/SSQ-53G Data Sheet

AN/SSQ-53G (GPS) DIFAR

The AN/SSQ-53G (GPS) DIFAR is the latest directional passive sonobuoy with GPS specifically made for international customers using ASCII NMEA code. Other than the GPS difference, it is identical to a 53G.

Download AN/SSQ-53G (GPS) Data Sheet

AN/SSQ-101B ADAR

The Air Deployed Active Receiver (ADAR) sonobuoy is the latest sensor with a horizontal planar array of 40 omnidirectional sensors and requires the newest airborne receivers and signal processing capabilities. The sonobuoy is primarily used as a receiver for multi-static operations. This sonobuoy transmits for a minimum of 4.5-6.0 hours over an eight hour period. Switching the VHF transmitter off when active acoustic signals are not being transmitted in the water extends the period of operation. This sonobuoy has four selectable depths (65, 175, 300, and 500 ft.). Depth, RF channel, Processing Mode and Band selection may be set via Electronic Function Selection (EFS) prior to launch and RF channel and Processing Mode and Band can be changed and VHF transmitter power can be switched on and off after deployment via digital Command Function Select (CFS).

Download AN/SSQ-101B ADAR Data Sheet

 

 

Active Sonobuoys

Target detection of a very quiet diesel submarine or a submarine in attack mode is very difficult, especially in extreme environmental conditions. In these situations, it is critical to localize the target quickly and accurately. This is when active sonobuoys are used. The released acoustic energy (“ping”) from an active sonobuoy and the resultant return signal enable accurate positioning of the submarine in both range and bearing. When two or more fixes are obtained, the speed and the course of the submarine can be established.

The following “A” size sonobuoys can be air-launched from fixed or rotary-wing aircraft since they all employ a parachute to retard their descent and provide descent stability. These sonobuoys are also easily deployable from the deck of a surface vessel. They also all employ a battery which is energized upon entry into salt water. As with the passive sonobuoys, once energized, a mechanism for inflating a float with CO2 gas is activated, suspending the sonobuoy. The sensors are then released to specified depths. These sonobuoys use a transducer to introduce acoustic energy into the water (“ping”) and except for the AN/SSQ-125 use the transducer to receive the return echoes which are then amplified and frequency modulated for VHF transmission. All of the sonobuoys scuttle after a preset length of operation.

AN/SSQ-62E DICASS

The AN/SSQ-62E Directional Command Activated Sonobuoy System (DICASS) is currently the primary active sonobuoy used internationally. DICASS permits the operator to pinpoint a target’s position in range and bearing. The AN/SSQ-62E has been in service since 2000 and offers operation on one of four acoustic frequencies (6.5, 7.5, 8.5, and 9.5 kHz) and the selection of one of two depth families. The effective source level of this sonobuoy varies with the acoustic channel between 199 and 201 dB. The U.S. stopped procuring the AN/SSQ-62E DICASS sensor in 2016 and has replaced it with the AN/SSQ-62F sensor with GPS. The 62E is still available at competitive pricing by removing features from newer model DIFAR sonobuoys.

Download AN/SSQ-62E DICASS Data Sheet

AN/SSQ-62F DICASS

The current generation of the DICASS family of active sonobuoys is the AN/SSQ-62F. This sonobuoy meets all specifications of the 62E plus has GPS that requires specific CFS commands being produced for most P-8 aircraft. The AN/SSQ-62F offers operation on one of four acoustic frequencies (6.5, 7.5, 8.5, and 9.5 kHz) and the selection of one of two depth families. The effective source level of this sonobuoy varies with the acoustic channel between 199 and 201 dB. Depth and RF channel can be set via EFS prior to launch and deeper depth, acoustic channel, RF channel, and RF Power On/Off can be changed after activation with CFS.

Download AN/SSQ-62F DICASS Data Sheet

AN/SSQ-62F (GPS) DICASS

The AN/SSQ-62F (GPS) DICASS is the latest active sonobuoy with GPS specifically made for international customers using ASCII NMEA code. Other than the GPS difference, it is identical to a 62F.

Download AN/SSQ-62F (GPS) Data Sheet

AN/SSQ-125

The AN/SSQ-125 Coherent Source is a NATO, A-size sonobuoy manufactured by SonobuoyTech Systems for use as a source in a multi-static field. The AN/SSQ-125 is capable of generating a variety of waveforms upon command and is designed to work with the AN/SSQ-53F/G and AN/SSQ-101B (ADAR) sonobuoys.

Download AN/SSQ-125 Data Sheet

 

 

Other Underwater Signaling and Receiving Devices

AN/SSQ-36B BT

Prior to deployment of any detection sonobuoys, it is advisable to have a vertical temperature profile of the ocean. The AN/SSQ-36B Bathythermal (BT) buoy provides a low-cost method to obtain vertical temperature profiles of a water column. This approach provides near synoptic area surveys while eliminating costly vessel time. The BT is widely used for airborne Anti-Submarine Warfare (ASW) applications to evaluate local effects of seawater temperature on sonar propagation and acoustic range prediction. This sonobuoy has an operating life of approximately 12 minutes at which the temperature probe is at a depth of 800 meters (2625 ft). The sensors are calibrated for an accuracy of ±1 degree F at a descent rate of 5 feet per second. VHF transmissions from this sonobuoy are processed to read temperature versus descent in real time. It can be air launched or over-the-side launched, is “A” size (can be “G” size), and is 99 channel selectable. The transmitter output is ¼ Watt.

Download AN/SSQ-36B BT Data Sheet

MK-84 MOD 1 SUS

The Signal Underwater Sound (SUS) device is used primarily for one-way acoustic communication with submarines. The device can be set to generate one of five distinct, coded sequences. Four of these sequences consist of a continuous tone that alternates in frequency in accordance with the timing sequence defined in the Code Table (see specifications). The fifth sequence is a continuous tone at a single frequency. Third harmonics of the fundamental frequencies are also generated at levels slightly less than those of the fundamentals. A five-position switch on the side of the unit accomplishes settings. The MK-84 is designed to provide a source level of 160 dB per micro-Pascal within two (2) seconds of water entry and throughout its one-minute life.

Download MK-84 MOD 1 SUS Data Sheet