FRANCE
TITLE : FLASH dipping sonar
TEXT :
FLASH (Folding Light Acoustic System for Helicopters) is a new
low-frequency helicopter dipping sonar with sonobuoy processing
capabilities developed by Thomson Marconi Sonar for a number of
applications. It operates at five frequencies below 5 kHz, with 24
preformed beams. The winch is capable of 750 m immersion depth at a
speed up to 10 m per second.
The system offers an FM mode to enable detection of low-speed
targets in shallow waters and strong reverberation conditions. With
its light weight and volume, the FLASH can be fitted on board light
ASW helicopters such as the Super Lynx.
Operational status
Thomson Marconi Sonar supplies FLASH, designated Sonar 2089 in the
UK, for the long-range dipping sonar requirement of the Royal Navy's
Merlin helicopter. This system combines the Thomson Marconi Sonar SAS
low-frequency array and winch with the Thomson Marconi Sonar Ltd
acoustic processor designated the AQS 950. Thomson Marconi Sonar has
also teamed with Hughes Aircraft Company for the US Navy's ALFS
requirement in which configuration it is designated AN/AQS-22.
The FLASH array and reeling machine have already been evaluated in
trials for the US Navy. The FLASH array, reeling machine, transmitter
and new acoustic processor are now being evaluated in flight trials by
the French Navy for the NFH 90 programme. Acoustic in-water testing
has been achieved in France, the UK, and the USA. The system is
currently in production.
COMPANY NAME : Thomson Marconi Sonar SAS
CAPTION : The FLASH long-range active dipping sonar
TITLE : Airborne Active Dipping Sonar
TEXT :
The Airborne Active Dipping Sonar (AADS) system consists of the sonar
array, reeling machine, sonar transmitter/receiver and signal and
display processor. It is designed to be fully compatible with all
types of maritime helicopters in service today.
The sonar transducer contains the acoustic projector for sonic
pulse generation and an expandable array of receiving hydrophones. The
projector resonates at the frequency and duration of the pulse
generated by the sonar transmitter. It is capable of producing maximum
acoustic source levels at any depth below 6 m. Centre frequencies are
selectable for optimal acoustic performance in different environments.
The expandable receiving array provides a large acoustic aperture for
increased sensitivity and directivity. The expanding mechanism is
designed to fail-safe standards to ensure safe retrieval of the
array.
Rapid deployment and retrieval of the sonar transducer is provided
by the lightweight reeling machine. Layering and stowage of the
required length of the extra strong cable has been tested with an MTBF
of 4,440 cycles. Replacement of cable and assembly can be accomplished
during the refuelling cycle.
The Sonar Transmitter/Receiver (STR) generates the transmit
waveforms and provides the output power to drive the acoustic
projector. It also processes the signal returns from the transducer
receive array. The STR is located in the helicopter cabin and provides
local control functions for the dipping sonar subsystem, including the
reeling machine, the acoustic transducer and the interfaces between
the dipping sonar system and the signal processor.
COMPANY NAME : Hughes Aircraft Company, Sensors and Communication
Systems
COMPANY NAME : Thomson Marconi Sonar SAS
AN/AQS-18 sonar for helicopters
TEXT :
The AN/AQS-18 is a helicopter long-range active scanning sonar. The
system detects and maintains contact with underwater targets through a
transducer lowered into the water from a hovering helicopter. Active
echo-ranging determines a target's range and bearing and opening or
closing rate relative to the aircraft. Target identification
information is also provided.
The AN/AQS-18 is an advanced version of earlier dunking sonars made
by AlliedSignal and includes digital technology, improved signal
processing and improved operator displays. The system consists of a
small high-density transducer with a high sink and retrieval rate, a
built-in multiplex system to permit use of a single conductor cable, a
330 m cable and compatible reeling machine and a lightweight
transmitter built into the transducer package. The Adaptive Processor
Sonar (APS), which provides enhanced performance in shallow water
areas, is an integral part of the system.
The AN/AQS-18 offers a number of improvements over earlier dipping
sonars. These include increased transmitter power output to give
longer range, high-speed dip cycle time and reductions in weight of
all units.
The APS increases detection capability in shallow water and
reverberation-limited conditions, while eliminating false alarms from
the video display. The APS is a digital processor which uses fast
Fourier transform techniques to provide narrowband analysis of the
uniquely shaped CW pulse transmitted in the APS mode. The PPI display
retains the normal readout of target range and bearing.
The APS processing gain improvement over the normal AN/AQS-18
analogue processing is 20 dB for a 2 kt target and 15 dB for a 5 kt
Doppler target. The higher energy transmitted with the longer pulse
APS mode, combined with the narrowband analysis, also improves
operation in the non-reverberant conditions more typical of deep
water. The gain improvement outside the 10 kt or greater high
reverberation zone under wideband noise-limited conditions exceeds 7
dB.
The latest version is the AN/AQS-18(V) which is available with both
300 and 450 m length cables.
SPECIFICATIONS :
Weight: 252 kg plus 13.3 kg for APS
Frequency: 9.23, 10, 10.77 kHz
Sound pressure level: 217 dB/µPa/yd (0.9 m)
Range scales: 1,000, 3,000, 5,000, 8,000, 12,000, 20,000 yds
Modes: 3.5 or 35 ms pulse (energy detection) and 200 or 700 ms pulse
(narrowband analysis)
Visual outputs: range, range rate, bearing, operator verification
Audio output: dual channel with gain control plus constant level to
aircraft intercom
Recorder operation: bathythermograph, range, ASPECT, MAD, BITE
Operating depth: 330 m
TEXT :
Operational status
In production and in service with the German, Greek, Itailian,
Japanese, Portuguese, Spanish, Taiwanese and US navies on Lynx, SH-3,
SH-60J and S-70C(M)-1 helicopters.
COMPANY NAME : AlliedSignal Ocean Systems
CAPTION : The AN/AQS-18(V) deployed from a German Navy Westland Lynx
Mk 88 helicopter
(1995)
AN/AQS-18(V) dipping sonar system
TEXT :
The AN/AQS-18(V) is the export version of the AN/AQS-13F helicopter
dipping sonar. These systems employ a transducer which is lowered into
the water from a hovering helicopter to detect and maintain contact
with underwater targets. Active echo-ranging determines target range
and bearing, and opening and closing rate relative to the helicopter.
Target classification indications are also provided.
The AN/AQS-18(V)/13F Series of dipping sonars is specifically
designed for ASW helicopters where great mobility is required for fast
reaction. AN/AQS-18(V)/13F equipped helicopters are well-suited for
redetection of contacts, target localisation and weapon delivery
against shallow and deep water threats. ASW helicopters are often
required to search areas which are difficult for other sensor
platforms, including shallow water with high noise areas, coastal
regions, constrained passages, high-density shipping lanes and areas
of concentrated naval activity.
Features of the Series include high source level to provide
long-range, shallow water signal processing for high reverberation
areas, capability to control, process and display sonobuoys in a
single integrated system, high-speed reeling machine to achieve
maximum depth and retrieval within 3 minutes and adaptable reeling
machine designs compatible with a wide range of helicopters.
AN/AQS-18(V)/13F systems include digital technology, improved
signal processing, extensive use of hybrid integrated circuits and
improved operator displays.
SPECIFICATIONS :
Weight: 275 kg total
Frequency: 9.23, 10.003 and 10.744 kHz
Operating depth: 440 m
Sound pressure level: 217 +-1 dB/µPa/yd (0.9 m)
Range scales: 0.9, 2.7, 4.6, 7.3, 11, 18 km
Modes:
(active) 3.5, 35 ms pulses, 200, 700 ms shaped pulses (passive),
(communicate) SSB at 8 kHz
Raise speed: 6.7 m/s average
Lower speed: 4.9 m/s
Water exit speed: 1.5 m/s
COMPANY NAME : AlliedSignal Ocean Systems
AQS-18A dipping sonar system
TEXT :
The AQS-18A dipping sonar system represents a development of the
medium frequency AN/AQS-18(V) dipping sonar. The dome control, reeling
machine and transducer of the AN/AQS-18(V) have been interfaced with a
powerful digital processor, control unit and colour display. The
advanced processing brings greater performance through high-resolution
digital processing, greater contact memory space and the flexibility
to increase the number of sonar beams, type and length of pulses and
menus of operator displays.
The AQS-18A has additional pulse lengths of 1.6, 3.2 and 4 seconds.
The longer pulses put more energy on the target and provide higher
Doppler resolution for maximum performance in high reverberation
shallow water conditions. An FM mode is available for extremely low
Doppler target detection and maximum range resolution. The total ASW
system improvement of the AQS-18A is 14 dB over current systems and
can provide more than four times the area search rate of the
AN/AQS-18(V).
The AQS-18A has spare processing power and space for additional
processing features such as computer-aided detection and
classification, multisensor target fusion, embedded training and
performance prediction based on environmental data collected during
past or current missions. MIL-STD-1553 databus protocol facilitates
integration with other aircraft subsystems and components. BIT eases
support and boosts availability. The new weapon-replaceable assemblies
have a significantly higher MTBF than current systems.
SPECIFICATIONS :
Weight: 265 kg total
Frequency: 9.23, 10.003, 10.774 kHz
Sound pressure level: 217 +-1 dB/µPa/yd (0.9 m)
Range scales: 0.9, 2.7, 4.6, 7.3, 11, 18, 29 km
Operating depth: 440 m
Modes:
(active) 3.5, 35 ms pulses, 0.2, 0.7, 1.6, 3.2, 4 s shaped; 0.625 s
FMs (passive), (obstacle avoidance), (communicate) SSB at 8 kHz
Raise speed: 6.7 m/s average
Lower speed: 4.9 m/s
Water exit speed: 1.5 m/s
TEXT :
Operational status
The AQS-18A is in production and has been delivered to the Italian
Navy.
COMPANY NAME : AlliedSignal Ocean Systems
TITLE : Low Frequency Active Dipping Sonar (LFADS)
TEXT :
LFADS is similar in size and weight to the mid-frequency
AN/AQS-18(V). LFADS has been installed on SH-3, EH-101 and SH-60
helicopters. The cable interface, sonar processor, sonar control unit,
display, reeling machine and control devices are common between the 10
kHz AQS-18 and the 1.38 kHz LFADS systems.
The LFADS is capable of depths up to 440 m, and has figure-of-merit
sufficient to achieve convergence zone detections in deep water, and
transmission/receive characteristics optimised for extremely long
ranges in shallow water. The low frequency capability designed into
LFADS using proprietary transducer and beam forming technology allows
multiple boundary interactions and reduced reverberation contamination
of the received signals. Use of high-resolution Doppler processing and
shaped pulses achieves detection of targets even at speeds as low as 1
kt. Extended duration FM pulses are available to detect the near-zero
Doppler target as well.
SPECIFICATIONS :
Operating depth: 440 m
Operating frequencies: 1.33-1.43 kHz
Source level: 220 dB/µPa/yd
Range scales: 1, 3, 5, 10, 15, 20, 30, 40, 60, 80, 100, 120 kYd; 0.9,
2.7, 4.6, 9, 14, 18, 27, 37, 55, 73, 91, 110 km
Operational modes: Active-CW to 10 s pulses (FM to 5 s pulses);
passive; UQC; raytrace
Raise speed (avg): 4.3 m/s
Lower speed (max): 4.9 m/s
Water exit speed: 1.5 m/s
Seating speed: 0.6 m/s
System weight: (stand-alone)
(Proc. & Display) 59 kg
(R/M & Cable) 95 kg
(Xducer) 141 kg
(Total weight) 295 kg
TEXT :
Operational status
LFADS has been demonstrated in differing water conditions, including
the Timor and Mediterranean Seas and Vestfjorden Fjord. Results of
these tests indicate that LFADS can even outperform shipborne systems
against diesel-electric submarines.
COMPANY NAME : AlliedSignal Ocean Systems
TITLE : HS 12 helicopter sonar
TEXT :
Type
Passive and active dipping sonar system.
Description
The HS 12 is an active/passive panoramic helicopter version of the SS 12
small ship sonar and uses the same electronics as the surface vessels
version. It has similar capabilities for operation in shallow/noisy
waters, and has a system weight of less than 240 kg, making it suitable
for installation on light naval helicopters such as the Lynx. The HS 12
transducer is raised and lowered by a hydraulic winch at a high speed.
Operation in CW and FM modes is possible and digital signal processing is
employed by the system's microprocessor. Automatic tracking of two
targets and transmission of elements to an external equipment, such as a
plotting table, are provided.
The system operates on 13 kHz in the active mode and in the 7 to 12 kHz
range passively. A total of 12 preformed beams is employed giving 30°
sectors, with a minimum range of about 10 km. The display consists of
four quadrants, these being obtained by processing adjacent beams. The
operator can select a CW mode which provides target range and Doppler. He
can also select FM processing, and a sector mode is also provided.
Operational status
In series production. Four Chinese SA-321G Super Frelon helicopters have
been equipped with HS 12 systems together with about 50 Chinese-built
Dauphin (Harbin) helicopters. It is also in operation in several other
navies including the Indian Navy where it equips Sea King helicopters and
the French navy.
SPECIFICATIONS :
Frequencies: Medium frequency band
Transmission level: >=212 dB/µPa/m
Passive search: Noise or pinger. Display of 12 preformed beams, each
subject to adaptive signal processing. Other characteristics as for the
SS 12
Total weight: 230 kg
COMPANY NAME : Thomson Marconi Sonar SAS
ADDRESS :
Sophia Antipolis.
CAPTION : Typical helicopter installation of the HS 12 sonar on Dauphin
naval helicopter
TITLE : FLASH dipping sonar
TEXT :
Type
Helicopter dipping sonar system.
Description
FLASH (Folding Light Acoustic System for Helicopters) is a new low-
frequency dipping sonar with sonobuoy processing capabilities developed
by Thomson Sintra ASM for a number of applications. It operates at five
frequencies below 5 kHz, with 24 preformed beams. The winch is capable of
750 m immersion depth at a speed up to 10 m per second.
The system offers an efficient FM mode to enable detection of low-speed
targets in shallow waters and strong reverberation conditions. With its
light weight and volume, the FLASH can be fitted on board light ASW
helicopters such as the Super Lynx.
Operational status
Thomson Marconi Sonar SAS is teamed with prime contractor Thomson Marconi
Sonar Ltd to supply FLASH (designated AQS 960 in the UK) for the long-
range dipping sonar requirement for the Royal Navy's Merlin helicopter.
This system will combine the French low-frequency array and winch with
the British signal and data processing expertise. Thomson Marconi SAS has
also teamed with Hughes Aircraft Company in the USA for the US Navy's
ALFS requirement in which configuration it is designated AN/AQS-22 (qv).
The FLASH array and reeling machine have already been evaluated in trials
for the US Navy.
The FLASH array, reeling machine, transmitter and new acoustic processor
are being evaluated in flight trials by the French Navy for the NH 90
programme.
Acoustic in-water testing has been completed in France and in the UK, and
hydraulic rig tests have been completed in Italy. During 1995, a
comprehensive series of environmental and in-water tests were carried
out.
COMPANY NAME : Thomson Marconi Sonar SAS
ADDRESS :
Sophia Antipolis.
CAPTION : Wet end of the FLASH dipping sonar
ITLE : DUAV-4 helicopter sonar
TEXT :
Type
Passive and active sonar system.
Description
The DUAV-4 is an active/passive directive sonar designed for submarine
surveillance and location (azimuth, distance and radial speed). It is
specially designed for use on board light, versatile, ship-based
helicopters such as the Lynx.
The DUAV-4 differs from conventional sonar in its signal processing
system, which is designed to give improved detection, especially in
severe reverberation conditions such as shallow waters. The sonar can be
operated in either the active or passive mode: true bearing, range, and
radial speed are measured in the former mode; true bearing only in the
passive mode.
A combined display unit permits surveillance display (initial detection)
or plotting display (precise azimuth determination). Total weight
including electronic rack, cable and dome is 250 kg.
Operational status
The DUAV-4 sonar is in active service with the French Navy, the Royal
Netherlands Navy and several other navies. Over 90 have been produced.
The French Navy has opted to replace it in some of the Lynx helicopters
with the HS 12 (see separate entry).
COMPANY NAME : Thomson Marconi Sonar SAS
ADDRESS :
Sophia Antipolis.
CAPTION : DUAV-4 helicopter sonar installation in Lynx
TITLE : Upgraded DUAV-4 helicopter sonar
TEXT :
Type
Active and passive dipping sonar system.
Description
The upgraded DUAV-4 or DUAV-4 UPG differs from the DUAV-4 in its
acoustic processor, which is now based on the SADANG new-generation
acoustic processor. This state-of-the-art system offers more powerful
signal and data processing, as well as improved man/machine interface.
The DUAV-4 UPG also offers specific software tools and operator aids
designed to meet the requirement for detection in shallow, rocky-bottom
waters.
Operational status
A DUAV-4 UPG prototype passed factory tests and at-sea trials and was
supplied to the Swedish Royal Navy in April 1992. Now operational at sea.
COMPANY NAME : Thomson Marconi Sonar SAS
ADDRESS :
Sophia Antipolis.
TITLE : AN/AQS-22 ALFS - Airborne Low Frequency Sonar
TEXT :
Type
Next-generation low-frequency dipping sonar.
Description
ALFS is a US Naval Air Systems Command project for a new generation
dipping sonar which will largely replace the existing AN/AQS-13F, and is
scheduled to be fitted on board the SH 60R (the upgraded version of the
SH 60F or B). No technical details have been announced, except that the
associated processor will be the UYS-2 manufactured by Lucent
Technologies. The UYS-2 has operator selectable full-band, eighth-band