NAVY C4ISR AND UNMANNED SYSTEMS
AIRBORNE SONAR SYSTEMS
101 WWW.SEAPOWERMAGAZINE.ORG SEAPOWER ALMANAC 2015
AIRBORNE SONAR SYSTEMS
AQS-24A MINEHUNTING SONAR
BRIEFING: The AQS-24A is an active sonar winched and towed
through the water by an MH-53E mine-countermeasures helicopter. It is designed to detect mines for further investigation by mine
warfare forces. The AQS-24A uses sonar simultaneously with a
laser line scanner to provide precision optical identification of
underwater mines. The sonar also has been ordered by Japan for
use on its minesweeping helicopters. The AQS-24A also is the
sensor for the Mine Hunting Unmanned Surface Vehicle.
CONTRACTOR: ...........Northrop Grumman (Westinghouse)
AQS- 22 AIRBORNE LOW-FREQUENCY
BRIEFING: The AQS- 22 ALFS is the primary anti-submarine
warfare sensor for the MH-60R multimission helicopter. The
ASQ- 22 is dipped into the water by a reel on the helicopter and
used to detect, track and localize a submarine. It also can be
used for passive acoustic intercept, underwater communications with a submarine and collecting bathythermal information
of the ocean. Low-rate initial production began in 2002 and full-rate production in 2006. The ALFS was first deployed operationally in 2009.
CONTRACTOR: ...........Raytheon Co.
AQS-20A MINEHUNTING SONAR
BRIEFING: The AQS-20A is a variable-depth underwater
mine-detection sonar designed to give a strike group an organic capability to detect, classify and localize bottom, close-tethered and volume mines. The AQS-20A also is fitted with an
electro-optic sensor to identify underwater objects. The sonar
is deployed while the helicopter is in a hover and then towed
undersea to scan the water in front and to the sides of the aircraft, as well as the sea bottom for anti-shipping mines. The
sonar and electro-optical sensor provide high-resolution
images of mines and mine-like objects as well as high-precision
The AQS-20A is a component of the Remote Multimission
Vehicle and the Airborne Mine-Neutralization System in the
mine warfare mission package of the littoral combat ship. The
AQS-20A entered low-rate initial production in 2005.
CONTRACTOR: ...........Raytheon Co.
USQ- 78(B) ACOUSTIC SYSTEM
BRIEFING: The P-3C’s USQ- 78(B) acoustic processor and display system upgrades the sonobuoy receiver to an all-digital
software-defined system, eliminates obsolete and proprietary
components, interfaces with an open-system architecture, and
provides processing and functionality growth for the life of the
aircraft. The USQ-78B is being installed in all P-3C AIP and
Block Modification Upgrade Program aircraft.
The Acoustic Receiver Technical Refresh (ARTR) program is
designed to provide replacement hardware and software for the
current P-3C acoustic suite that has components nearing the
end of their useful lives. Additionally, ARTR is designed to add
some Radio Frequency Interference mitigation techniques along
with an embedded sonobuoy recording capability. Major components replaced by the ARTR are the Advanced Sonobuoy
Communication Link (ASCL) receivers, ASCL pre-amps,
acoustic distribution boxes, Command Active Sonobuoy System
transmitter, acoustic data recorder(s), Time Code Generator and
Acoustic Test Signal Generator. New hardware consists of a
Software Defined Sonobuoy Receiver (SDSR), Command
Function Transmitter, Quad External Preamplifier, Embedded
Acoustic Data Recorder and an SDSR 4 antenna array.
CONTRACTOR: ...........Lockheed Martin Corp.
BRIEFING: Sonobuoys are used for environmental measurement and prediction prior to and during an ASW operation, passive and active acoustic search and localization of the submarine
target, and final active acoustic fixing of the target position.
Sonobuoys are expendable sensor systems designed to be
dropped from aircraft into the water, where the parachute-retarded or speed-braked cylindrical housings deploy battery-powered cables with passive acoustic hydrophones or active
transducers for detecting, tracking and collecting acoustic intelligence on submarines and surface ships and radioing the information to the aircraft or a ship for processing.
The SSQ- 36 bathythermograph sonobuoy is used to graph
the temperature profile of a body of water. The SSQ-53F
Directional Frequency Analysis and Recording System is a passive acoustic sensor for detecting, localizing and tracking a submarine. The SSQ-77C Vertical Line Array is a passive directional buoy with multiple hydrophones in a vertical column and can
be used as a multistatic receiver or a passive sensor. The SSQ-
62E Directional Command Activated Sonobuoy System is an
active sensor used to provide terminal positioning data during
the attack phase by transmitting active sound and determining
range and bearing to a contact.
The SSQ-101 Air Deployable Active Receiver is a commandable, passive acoustic sonobuoy with a horizontal planar array.
The SSQ- 125 is the coherent source sonobuoy used in the
Multistatic Active Coherent (MAC) Air ASW system. It replaces
the SSQ- 110 used with previous impulsive multistatic systems.
The SSQ- 125 produces electronic (coherent) pulses of various types and lengths that enable Doppler processing to distinguish moving targets (e.g., submarines) from stationary features
of the environment (e.g., shipwrecks). This capability will
enable the detection of targets in shallow water environments
involving a rough ocean floor. In a planned second phase of
MAC development, the power source for the SSQ- 125 will be
increased, enabling it to attain the long-range search capabilities
required for deep convergence zone environments. High-altitude ASW will integrate modified sonobuoy sensors to
enhance the P-8A capability to conduct its mission at altitudes
higher than traditional fixed-wing airborne ASW, thereby
enabling greater communications range.
CONTRACTORS:.........Sparton Corp., Ultra Electronics’ UnderSea
Sensor Systems Inc., ERAPSCO (joint venture
between Sparton and Ultra)