Locational anti-mine systems are mainly created on the basis of lidars (LIDAR - from "Light Detecting And Ranging"), which are laser locators that allow using laser radiation to perform depth measurement and seabed mapping, as well as to accurately detect, identify and classify various objects. located in the water column or on the seabed. Including small objects, which is especially important when examining certain important areas of the marine area, especially coastal zones and narrows. At the same time, an important feature of laser location (search) systems is the relatively high secrecy of their use - unlike, say, traditional search trawling with the help of mine-sweeping ships or minesweeper helicopters or the use of anti-mine uninhabited underwater vehicles. Consider some of the anti-mine laser location systems.
Mina is looking for "Magic Lantern"
Helicopter SH-2G "Super Sea Sprite" aviation US Navy equipped with the Magic Lantern laser ranging system (container suspended from the side of the fuselage)
The first relatively successful attempt to create a laser radar (search) anti-mine system, capable of accurately searching for, detecting and classifying sea mines of various types, was the Magic Lantern complex, which was developed by the requirements of the US Navy. located in Tucson, Arizona, the Center for the development of optical-electronic systems of the company "Kaman Aerospace Corporation".
The initial stage of testing this system took place as early as 1988, and then its modified version of the aircraft (helicopter) based, designed to detect and classify mines, minimized objects, as well as various elements of anti-airborne barriers, was accepted for trial operation in the US Navy. and passed a "battle test" during the operation "Desert Storm".
"Magic Lantern" is a search anti-mine system, built on the basis of a pulsed solid-state laser on a yttrium-aluminum garnet with neodymium. The system includes the actual laser setup with a radiating device, a scanning optical device, six cameras with intensified CCD matrices (ICCD; CCD is a charge coupled device), a device for automatic recognition of targets in real time, as well as two-way communication equipment, a computing unit (COMPUTER) and a number of supporting systems.
The principle of operation of this system can be described as follows. The laser transmitter sends a beam in the direction of the water surface (the direction of the laser beam is perpendicular to the direction of flight of the aircraft carrier system), while the electronic shutters of the cameras are opened by means of pulsed synchronization generators and thus receive a laser beam reflected from objects located in the water column. Each camera was tuned to its own depth range, which was set in advance, which made it possible to obtain fairly accurate data on the depth of a mine or other minimized object.
In the first half of the 1990-s, eight SH-2G Super Sea Sprite helicopters from the 94 light antisubmarine helicopter squadron of the US Navy Reserve were re-equipped into the Magic Lantern system. In the photo - one of the SH-2F squadrons during refueling over the deck of the American frigate URO FFG-11 "Clark"
A special feature of the “Magic Lantern” was the high resolution and selectivity of the cameras, which allowed us to confidently distinguish laser pulses reflected from various objects and the seabed. Moreover, images of mines and mine-like objects obtained as a result of processing the reflected pulses were automatically cataloged, classified and archived in the onboard computer memory. The results were available in real time for analysis by the operator - the information was displayed on the display display of the tactical situation of the ASN-150 type, located on the dashboard in the cockpit of the helicopter carrier. Although more thorough processing and analysis of the obtained data, as noted in foreign sources, were still to be carried out at the coastal control post, where information from the helicopter of the carrier was transmitted in real time.
The equipment of the “Magic Lantern” system was placed in a container of length 1,22 m, which was suspended on a pylon from the starboard fuselage of the helicopter carrier. According to American sources, a helicopter equipped with the Magic Lantern system could, within one hour, explore the water area of about 6 square miles (approx. 15,5 sq. Km).
The prototype of the Magic Lantern was tested to explore the possibility of its being included in the integrated mine defense system, which the US Navy command planned to use in the process of providing amphibious landing operations to search for and detect various types of mines in shallow coastal areas with depths up to 12 m.
Amphibious helicopter carrier "Tripoli" after an explosion on an Iraqi mine. A huge hole in the underwater part of the hull is clearly visible, requiring long and expensive repairs.
The prototype of this system was used to mine support operations of the US Navy in the first Gulf War (1991). The decision to transfer a laser location system to the Persian Gulf was made, as indicated in foreign official sources, immediately after the Tripoli helicopter carrier (of the Iwo Jima type) was blown up on an Iraqi mine in the area that had previously been “processed” mine-sweeping forces of the American fleet (ship repair took 30 days and cost $ 15 million). During operation in the Gulf, a high probability of detecting floating, buried and anchor mines was confirmed, but there were difficulties with the accuracy of detection of bottom mines.
After the elimination of the revealed remarks, the development company assembled and transferred to the US Navy three modified systems, called “Magic Lantern Deployment Contingency” or ML (DC) and including, in addition to the main laser radar (search) unit, a space radio-navigation system receiver (CRNS), which allowed with high accuracy to determine the coordinates of identified mines and other dangerous objects, making maps of minefields, anti-landing barriers and other obstacles.
In the middle of the 1990-s, eight SH-2G Super Seasprite helicopters from the 94-th light anti-submarine helicopter squadron "Titans" (HSL-94 Titans) of the US Navy Reserve, were converted into carriers of the Magic Lantern laser location-based anti-mine system. October 1 formed 1985 and stationed at Willow Grove airbase, Pennsylvania. Subsequently, the ML (DC) system was modified for use on the MH-53 "Sea Dragon" anti-mine helicopters. The tests of the “Magic Lantern” at the last were successfully completed at the end of January 2002, and in total for MH-53E helicopters three such systems were finalized. Helicopters stationed on the basis of the Command of the Naval Systems of the US Navy in Panama City.
To date, the “Magic Lantern” system has been decommissioned, but all the kits are in conservation at the US Navy’s ministry and anti-submarine command depot and can be quickly returned by decision of the head of the mine-main component of this command. on carriers in emergency situations. Some time ago, the possibility of reworking the Magic Lantern system for use on unmanned aerial vehicles (UAVs) adopted by the US Navy was also studied.
SM 2000 system
The Northrop Grumman division of the corporation engaged in the development of various naval systems, as well as tools for studying and developing the World Ocean, was the next to turn to the topic of laser systems for the search and detection of sea mines. In the interests of the US Navy, its specialists have developed a laser location system, which was originally included in the upgraded AN-AQS-14A (V) 1 aircraft-based towed anti-mine system.
The SM 2000 laser locating system — a civilian version of the similar military design developed by Northrop Grumman — was tested in the US Navy Pacific Fleet in order to explore its search capabilities at the bottom and in the water column of various explosive objects
The latter entered service with the US Navy in the middle of the 1990-ies, and the first eight sets of this system, the basis of which is the side-view GAS, were transferred to the US Navy in 1995 and installed on the CH-53 “Sea Dragon” helicopters. The AN / AQS-XNUMHA system was also adopted by the MN-14E helicopters of the Japanese Navy. However, the laser location system was later offered as an independent means of searching and detecting sea mines, and under the designation SM 53 was introduced by the development company to the civilian market (hereinafter, we will provide technical parameters for the commercial modification of SM 2000).
This system was created on the basis of a pulsed solid-state laser on a yttrium-aluminum garnet with neodymium with a working wavelength of 532 nm, which provides a highly accurate picture of the aqueous medium depending on its degree of transparency within a radius of 2,5-38 m (in a number of sources it is indicated that in SM 2000 uses ionic argon laser, but this statement is not true). At the same time, the resolution of the system at a depth of 7,5 m is 0,3 cm, and at a depth of 30 m it is not worse than 1,2 cm, which allows not only detecting various types of sea mines, but also fairly confidently identify them.
A distinctive feature of the system is a relatively low level of power consumption in the operating mode - no more than 100 W in continuous mode and no more than 250 W during peak loads.
It should be noted that the working wavelength chosen by the developer, 532 nm, allows, according to foreign experts, to ensure the minimum possible attenuation of the laser beam as it passes through the water column, and in the daytime also provides a more effective “sifting out” of interference arising from the reflection from the water rays of daylight (sunlight).
The high performance of the SM 2000 system was demonstrated in the middle of 1996, when the US Navy specialists used it to search for the wreckage of the Trans World Airlines Boeing 747-131 airliner following 17 on July 1996 on the TWA 800 flight and shortly after takeoff exploded in air, and then fallen into the Atlantic Ocean near Long Island, New York. The working unit of the system went down to a depth of about 30 m and allowed the search team to quickly and accurately detect the wreckage of the aircraft.
SM 2000 is lowered overboard a research vessel during a routine test.
The SM 2000 system includes a work unit that is recessed into the water, as well as an operator console located on board the carrier (helicopter or surface ship). In turn, the working unit includes a laser emitter (transmitter), an optical scanner and a photoelectric multiplier. The principle of operation of the system is based on scanning the water column with a narrow laser beam ahead along the course of following the media equipped with the SM 2000. The beam reflected from an obstacle (bottom, artificial or natural objects, including mines, etc.) is caught by the receiver (optical scanner), which allows you to form and display a digital image of the surveyed area of the water area with the required accuracy. In order to compile reliable maps of the water area, including the seabed, and to obtain the exact coordinates of the detected objects, the SM 2000 system can be interfaced with a GPS CRNS receiver.
The overall dimensions of the working unit of the system supplied to military customers are not made public by the developer, but similar parameters of the civil modification of the SM 2000 are known: weight - 163 kg, length - 1752 mm, diameter - 279 mm. The use of the SM 2000 system is possible at media speeds from 0,5 to 10 nodes, and the working unit can be buried deep in water to 1525 m. Depending on the preset operating parameters and operating conditions (towing), the working unit of the SM 2000 system allows you to explore the water section width from 3 to 61 meter at a viewing angle 15-70 degrees.
In conclusion, we note that the commercial SM 2000 system as part of a remote-controlled underwater complex developed by Science Applications International Corporation was used in the US Navy Pacific Fleet to test for detection of various underwater objects, including the detection of unexploded ordnance and so forth
AN / AES-1 system
The AN / AES-1 system was originally designed with the possibility of including littoral warships (LCS) as part of the mine-defense module, all of whose assets are housed in a standard shipping container.
Another laser location system designed to search and detect sea mines, and being commercially available and in service with the US Navy, is the AN / AES-1 ALMDS (Airborne Laser Mine Detection System), an aeronautical mine-based laser system developed by specialists from the Integrated Systems "Northrop Grumman Integrated Systems, Inc., and intended for the anti-mine support of naval strike groups (especially aircraft carrier and amphibious assault forces) when crossing pouring zones, narrowness and other areas, potentially mines, as well as operational mine action support for amphibious assault operations.
An important feature of this system is that from the very beginning it was decided to include in the so-called mine-defense module (mine-warfare mission module) littoral warships (LBK), as part of which it was supposed to provide an effective search, detection, classification and determination of the exact coordinates of floating, drifting and submerged mines, as well as anchor mines located at a distance of 15 m from the water surface.
In April, the US Navy command issued to Northrop Grumman a contract worth $ 2000 million, according to which she was to develop the system and build a prototype. In this case, the customer demanded to provide the widest possible overview of the water area in a single pass at high speed, which directly affected the design features of the system.
The MH-53 “Sea Dragon” helicopter from the 15 th mine bombardment squadron of the United States Navy (HM-15) with GAS side launch AN / AQS-14A. The composition of this system originally included the laser location system AN / AES-1. Arabian Sea, November 7 2003
AN / AES-1 is a container-type laser location system in which there are no complex mechanisms for driving the scanning unit, as is the case, for example, on conventional radar. The ship-based helicopter MH-60S "Knight Hawk" was chosen as the carrier of this system. The container with the AN / AES-1 system is suspended on the pylon from the left side of the helicopter by means of a standard bomb holder of the BRU-14 type. The direction of the laser beam is down-forward along the flight path of the carrier.
The actual container in which the equipment of the laser location system under consideration is located, according to the developer, has a length of 2,72 m, a diameter of 0,533 m and weighs about 365 kg. Starting from the front part, there are: a life support system, a central compartment with electronic equipment, a container sealing system (pressurization), a laser unit (together with a laser transmitter), receivers of laser beams reflected from obstacles, which are four cameras , as well as the power supply and control unit. The operation of the AN / AES-1 is controlled from the dashboard in the cockpit of the MH-60S helicopter, the same data is displayed on the multifunctional indicators - the results of scanning water space.
The developer, in turn, built the laser unit on the basis of a laser locator, lidar, with a pulsed solid-state laser on a yttrium-aluminum garnet with neodymium with a working wavelength of 532 nm, a pulse duration of 9 not, and an operating frequency of 100 Hz. Moreover, the lidar for this system was developed by the specialists of Arete Associates on the basis of a special technology patented by it, called STIL - from Streak Tube Imaging LIDAR, which can be translated from English roughly as "Lidar with an electron-optical device with a time resolution." In this case, in the working circuit, a pulsed laser emitter and an electron-optical device (camera) with a time resolution are used, which makes it possible to obtain a three-dimensional (in three coordinates) image with a high resolution not worse than 1,25, see.
Helicopter MH-60S "Knight Hawk", equipped with a laser location system AN / AES-1
In the mine action system, this technology allowed the detection of various sea mines in an automatic mode with high efficiency, and thanks to the use of a special algorithm, they were classified. A picture is displayed on the final device, in which the shape and size of the mine (object) is displayed, as well as its exact location in the water (if there is a CRNS receiver, the exact geographic coordinates are also available). In addition, the system allows you to simultaneously generate an accurate map of the seabed in the surveyed area of the water area (of course, within reach of the depth). Full processing of information obtained using the system is carried out by operators on board the ship, to which the carrier helicopter is assigned.
After receiving the above contract for the development and testing of the AN / AES-1 system, the company completed the necessary work in accordance with the schedule and in April 2004 began to test a prototype on board the MH-60S helicopter specially assigned for this purpose. The tests were quite successful, and 16 June 2005 was the official representative of the US Navy announced that Northrop Grumman had completed the development and demonstration of the system’s capabilities and was ready to begin the low-volume production. At the same time, the representative of the US Navy said that the command of the US Navy intends to purchase 2011 system kits AN / AES-57 before the 1 fiscal year (inclusive, but this did not happen).
13 September 2005 company Northrop Grumman received a contract number 61331-05-C-0049 worth 124,5 million dollars, which was to be completed in two stages:
- at the first stage - in the framework of small-scale production, assemble and deliver to the fleet three sets of AN / AES-1 (LRIP 1; cost of work - 45,5 million dollars);
- at the second stage - to deliver six containers as part of small-scale production, plus transfer to the customer the first production batch of six containers, two training kits and provide the necessary logistical support. This stage was arranged in the form of an option, the cost of it was estimated at approximately 79 million dollars, and the specific ordering should be made out in the form of separate additional contracts.
The X-2J group of servicemen from the Navy Aviation Systems Command and Northrop Grumman specialists just successfully flew the MH-60S helicopter equipped with the AN / AES-1ALMDS system, the first flight as part of the final flight test phase. Office of the US Navy Surface Weapons Development Center, Panama City, Florida. 8 June 2010
The first AN / AES-1 system was handed over to the US Navy in January 2007 during a ceremony organized at the Northrop Grumman facility in Melbourne, Florida. Until March, she passed the first stage of ground tests, after - the second stage of ground tests in a specialized center in Panama City, and then successfully passed the stage of flight tests.
6 March 2008, the company received an additional contract worth 2005 million 24 thousand 912 dollars for the production of the second small-scale batch of three sets of AN / AES-910 (LRIP 1) as part of the contract from 2. The last of which was delivered on March 11 2010
24 June 2010. Under the contract from 2005, Northrop Grumman received an additional contract worth $ 9,5 million for after-sales maintenance of the supplied systems, including their repair, modification and customization, and on September 29, the company Received contract No. 61331-10-С-0023 worth a little more than 45 million dollars (45.016.222 dollars) for the supply of a third small-scale batch of a four-set laser based radar system, as well as various spare parts and technical th support. However, 5 on April 2012 of the Navy gave the company a new contract worth 27 million 58 thousand 492 dollars, according to which the number of sets in LRIP 3 was increased by three.
In 2012, the AN / AES-1 ALMDS system successfully passed the operational evaluation and testing phase and was adopted by the US Navy as part of the on-board armament of the MH-60S helicopters and the LBK anti-mine defense module element. It should be noted that the Command of the US Naval Naval Systems (NAVSEA) in the future intends to expand the practical application of the AN / AES-1 system as regards the spectrum of tasks to be solved (it is believed that AN / AES-1 can be used with high efficiency for solving problems of PLO, in the fight against various surface targets, as well as in the framework of port security, assigned to the forces of the US Coast Guard), and in terms of expanding the list of carriers of this system. In particular, it is planned to explore the possibility of using this system on BPA aircraft of the P-3 “Orion” and P-8A “Poseidon” types, plus, in the future, the command of the US Navy does not exclude the possibility of equipping large UAVs with these systems US Navy weapons.
Simplified combat use of MH-60S helicopters equipped with a AN / AES-1 laser location system
In addition, the AN / AES-1 laser location system is planned to be included in the so-called “Aviation Rapid Mine Reduction System” or RAMICS (from the Rapid Airborne Mine Clearance System), which is designed to combat the floating, anchor and bottom mines, which will be detected various search engines, including laser radar, and destroyed using the 30-mm automatic gun Mk.44 "Bushmaster". The development of the AN / AWS-2 RAMICS system is carried out for the US Navy by Northrop Grumman.
In conclusion, it is worth noting that at the beginning of February 2012, the company received the first contract for AN / AES-1 systems from a foreign customer - the command of the Japanese Navy decided to purchase four sets of AN / AES-1 systems for use in coastal protection and ensure the safety of navigation at sea.
Japanese admirals chose MSN-101 (AW-101) helicopters, jointly produced by Agusta Westland and Kawasaki and currently in service with Japanese fleet aircraft (the Japanese Navy plans to acquire 11 helicopters, the first delivered in 2007, and the transfer of the latter is scheduled for 2015).
Moreover, the contract provides for not just the delivery of kits, but joint work with Japanese companies Kawasaki Heavy Industries and Fujitsu Limited. The latter will carry out the integration of the system aboard the MCH-101, which are currently already equipped with an anti-mine search system AN / AQS-24A on the basis of the GUS side-view.
“The ALMDS system installed on the MCN-101 helicopter will allow the Japanese Navy to cover a large area of water with the speed of the helicopter carrier,” noted Donna Carson-Jelley, head of the US Navy's ALMDS program in this regard. “The ALMDS system allows mine defense assets to go far ahead of the threats they are fighting against.”
For the Swedish Navy
Helicopter MSN-101 of the Japanese Naval Forces in the carrier variant of the laser location anti-mine system AN / AES-1
In the second half of the 1990-ies, a Canadian company Optech Inc. (Toronto, Ontario) developed a laser location system Hawk Eye for solving the problems of PLO and German specialists in a joint German-Swedish project. MIP in coastal and shallow areas. Tests of the prototype system were carried out jointly by the German and Swedish Navy in the waters of the Baltic Sea in September 1999.
At the same time, the German and Swedish sailors solved different tasks during the tests, which indicated a different approach to the practical application of the laser radar system:
- Swedish sailors tested the Hawk Eye system for solving various experimental tasks and for solving problems of military use of the system in the version of aviation, helicopter, and basing;
- German experts conducted tests of the ship-based system to study its capabilities for solving military tasks, as well as its applications for solving navigation problems and in oceanographic research (seabed mapping, water pollution level measurement, etc.).
The test results were quite promising. In particular, the Falcon Eye was proven to detect anchor mines with sufficiently high efficiency, although the reliability and accuracy of their detection depended on the conditions in the area of work (waves, water transparency, etc.). On the other hand, the search and detection of ground mines with the Hawk Eye system was significantly less effective. First of all, due to the occurrence of a multitude of interferences caused by multiple reflections of impulses from the seabed and the inability of the data analysis and processing subsystem to accurately select signals reflected from the mine itself and from the bottom section on which it was located.
Swedish experts, during tests of an aircraft-based modification, empirically found that in Baltic conditions a laser scanner can “pierce” the water column to a depth of about 12-15 m, allowing you to confidently detect a 10 cubic meter of 1% at 95 depth.
However, according to test results, it turned out that the system is not able to classify detected mines and mine-like objects with high efficiency, although the experts who took part in the tests considered it possible to eliminate this disadvantage by introducing more advanced data processing algorithms, using shorter operating pulses and more efficient computers.
All this did not leave any special chances for the active use of the Hawk Eye system in the interests of the military. In the end, it in a modified version was adopted by the Royal Swedish Navy in the amount of two sets and is currently used by specialists of the Hydrographic Office for solving “peaceful tasks” and for “detecting various targets”.
The main component of the Swedish system "Hawk Eye" is a receiving and transmitting unit, which includes a pulsed solid-state laser on a yttrium-aluminum garnet with neodymium, which, unlike a similar system developed for the US Navy, has two operating frequencies - 532 nm (" green "range) and 1064 nm (infrared range). Pulse duration - 7 not, frequency - 200 Hz.
The infrared ray is reflected from the water surface, which makes it possible to determine whether the carrier is under water, not the earth’s surface, and the distance to it, and the green ray penetrates into the water column and is reflected from the desired object (mine, obstacle, etc.) and from the seabed. The depth of penetration of the beam into the water column depends on the state of the sea and the attenuation coefficient of the beam in the water.
The reflected infrared beam is fed to an optical receiver, which includes a telescope (optical tube), beam splitters, filters, diaphragms and receivers, and a reflected green beam - to a photomultiplier tube and a avalanche photodiode. The review sector can range from 15 to 50 milli radians. The depth of the object can be determined by the difference in the time of reception of pulses reflected from the water surface (IR pulse) and from the object itself ("green" pulse), of course with the use of appropriate corrections, etc.
Summing up our brief review, it can be noted that in the foreseeable future, laser location (search) systems may well become one of the most effective means of detecting sea mines, as well as other underwater objects dangerous for ships (ships) and enemy antiamphibious elements. This circumstance is primarily due to the high information content of such systems; the absence of signs unmasking characteristic of search engines based on the GUS or trawls; high performance and mobility of such systems placed on board aircraft (helicopters, and in the future - airplanes and UAVs), as well as high accuracy in identifying the desired objects.
However, at this historical stage, the more active distribution of laser radar mine action systems is hampered by a number of shortcomings inherent in such systems, the most important of which can be considered a high dependence of their efficiency on water transparency and weather conditions in the search area, as well as a rather significant limitation in the detection depth of objects.