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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare Chapter 2 Mine Warfare The post-Cold War environment and the disappearance of the Soviet naval threat have reduced the Navy's focus on the blue waters of the open ocean and instead concentrated its attention on the littorals of the world. During the Cold War, the Navy was sized and configured to engage the Soviet fleet and its land-based naval air. Focused attention on the Soviet blue water threat resulted in comparative neglect of the unique requirements of operations in close proximity to land. As an aside, it is ironic that the Navy-Marine Corps team actually fought all its wars during that period—Korea, Vietnam, Grenada, Persian Gulf—in the littoral regions. Today and for the foreseeable future, the nation will require a Navy different from the one that was developed to counter the Soviet threat. The phrase, ''we will never again be faced with an opposed amphibious assault," first articulated in the 1960s, is heard no more. The panel foresees an increasing number of instances where the Navy and Marine Corps will be required to operate freely in near-shore waters, and the forces at their disposal, including MCM forces, should be configured such that they are able to operate effectively in these environments. At the same time, during the projection period of this study (2000-2035), a blue water threat may again emerge. Thus, the Navy of the future will require a balanced capability that can sustain operations in both the blue water and the littoral environments. The experiences of Wonsan in the Korean conflict and Kuwait in the Persian Gulf War indicate that sea mines, in the hands of a far lesser power that knows little of how to use them, can defeat, at least temporarily, the most powerful navy in the world. Today at least 45 countries, in addition to the United States and the
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare former Soviet states, possess mining capability, and any nation can acquire such a capability in a matter of months. At least 21 countries are known to produce mines, and 13 are confirmed mine exporters. The People's Republic of China, for instance, has sold copies of Russia's AMD/KMD II bottom influence mines in both the 500- and 1,000-kg versions and has marketed its own rocket-propelled mine, the EM52, designed to be deployed in relatively deep water against both submarines and surface ships. Yugoslavia produces mines based on Russian designs. Italy produces the Manta and computer-controlled MP-80 influence mines. It was a Manta mine laid in about 60 feet of water that seriously damaged the hull of the USS Princeton (CG-59) during the Persian Gulf War and disabled its Aegis antiair combat system and vertical launch system (VLS) missile batteries. Chile offers three mines for sale, including a microprocessor-controlled magnetic influence mine, the MS-L, and a version targeted at landing craft, the MS-C. Unfortunately, the known 45 producers of mines do not, in themselves, define the threat since virtually any country can produce an effective mine. It was the LUGM-145 moored contact mine produced by Iraq that damaged the USS Tripoli (LPH-10) during the Persian Gulf War. Further, mines do not have to be of modern design to pose an effective threat to naval operations. The mines used by Iran during Operation Ernest Will were from the Russo-Japanese War (1904-1905) with two upgrades. Many of the Turkish mines in the Dardanelles that forever changed world history during the Gallipoli campaign of World War I were Russian mines that floated through the Bosporus and were salvaged, refurbished, and replanted. Although mines can be cheap and simple, countering mines will most probably become more difficult due to increasingly sophisticated fusing methods and the ease with which mine signatures can be reduced. Miniature solid-state firing mechanisms and logic processors will allow increasingly complex acoustic-, magnetic-, and pressure-triggered mines that will evade existing sweeping techniques. Mines with reduced acoustic signatures will seriously degrade the performance of mine hunting sonars. The plastic-hulled Manta and the wedge-shaped Swedish Rockan GMI-100 are current examples of reduced signature mines that are believed to be difficult to detect. It is not unreasonable to expect to encounter mine systems that use distributed sensors and remote command and control (RECO) activation or deactivation through acoustic or electromagnetic links. During the past 45 years, in spite of the very modest effort devoted to mine design the explosive charge carried by the typical mine has essentially doubled in energy output; its instrument section has been reduced from 20 percent of its volume to a space the size of a soda can through the adoption of modern electronics; its lethality range has increased from a few tens of feet athwart ship to a half mile through the use of mobile warheads; its logic systems have been made more resistant to countermeasures; and through the use of stealth technology, its ability to evade mine hunting sonars has increased. Future naval forces will be confronted with more capable mines made possible by evolving technology.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare Prominent among the mine designs likely to be encountered between now and the year 2035 are (1) the self-burying mine, which would so degrade the performance of current mine hunting sonars as to force increased dependence on slower mine sweeping techniques; (2) another doubling of the warhead's energy output and continued reduction of the instrument section, thus increasing the delivery capacity of all mine laying platforms; (3) the introduction of alternating magnetic (AM), underwater electric potential (UEP), and possibly, pure pressure mine sensors; (4) the introduction of distributed sensor minefields in which the long-range multiple-shot kill component is located at a single point within or about the field; (5) mines specifically targeted against mine countermeasures (MCM) platforms, including helicopters; (6) the use of powerful minicomputers to increase the mine's target discrimination and resistance to countermeasures; and (7) whole minefields capable of remote command-on and command-off control and of changing sensitivity settings, sensor combinations, countermeasures logic, and even location on remote command. None of the possible advances enumerated above are particularly new, and all are within the reach of current technology. New technology developments will enable the design and fabrication of even more capable mines. The Panel on Undersea Warfare chose to utilize the classified Naval Studies Board report Mine Countermeasures Technology1 as starting point for its examination of mine warfare technology. The panel also took account of the 1995 White Paper issued by the Chief of Naval Operations2 calling for a major sea change in the Navy's approach to MCM operations. Specifically, Admiral Boorda directed that the Navy's MCM force be transformed from a dedicated on-call force to an organic force capable of traveling at battle group speeds, and that MCM be mainstreamed into the fleet as a professional competency at all ranks and rates. The panel's deliberations were guided by a view of MCM capability that enables effective pursuit of the following three objectives: (1) reduce the mine threat to its absolute minimum at each phase of an operation; (2) obtain maximum leverage of all available MCM assets; and (3) reduce the size and weight of all MCM systems without sacrificing capability. The panel believes that these objectives can be achieved and that a balanced MCM force, organic to the fleet and capable of removing the mine threat in keeping with an assault timetable or power projection schedule, can be achieved at relatively modest cost by the year 2005. Further, the panel has identified technologies whose far-term development would provide the Navy and Marine Corps team with an effective MCM capability well into the mid-21st century. 1 Naval Studies Board. 1992-1993. Mine Countermeasures Technology, Vol. I-IV, National Academy Press, Washington, D.C. 2 Boorda, J.M., ADM, USN. 1995. "Mine Countermeasures-An Integral Part of Our Strategy and Our Forces," White Paper, Office of the Chief of Naval Operations, Washington, D.C., December.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare The mine threat is expected to grow in technical sophistication over the projection period of this study; there is a substantial likelihood that mines will be developed that are difficult to detect and/or sweep. To deal with this issue, and more immediately with the threat of high-density minefields in the surf zone and on the beach, the panel addressed a number of so-called brute force technologies that deal with groups of mines, rather than single mines and obstacles, and do not depend on specific mine characteristics such as acoustic or magnetic signature, the type of fuse employed, or details of how the mine is deployed. The panel restricted its consideration mainly to sea mines and to mines and obstacles found in the surf zone and the craft landing zone. MINE COUNTERMEASURES: A VITAL CAPABILITY FOR FUTURE NAVAL MISSIONS The Navy of the future will be expected to maintain sea control; to transit and operate worldwide at will; to navigate restricted waters, open channels, and sea lanes; and to project power ashore. It will be expected to land forces, supplies, and equipment rapidly and safely to support national objectives. Unless properly countered, mines will restrict, if not prevent, the Navy from carrying out these missions. Technology in mine and countermine warfare in the next 30 years will be different than in the past because of (1) replacement of the Cold War preoccupation with port breakout, with the need for power projection into newer, troubled areas, which entails the protection of far-flung battle groups against mines, the clearance of shipping lanes, and in extreme cases, amphibious assault; (2) present and future reductions in defense budgets, which require that goals be pursued in the most cost-effective manner; and (3) the need to carefully integrate political and humanitarian with military imperatives, such as weapon choice, in the context of global peace. Changes are required to meet the new missions and rules of engagement. Battle groups can no longer rely on a dedicated MCM force to provide protection against mines everywhere and anywhere. Each battle group must assume responsibility for self-protection against the mine threat with new organic MCM capabilities. The present, dedicated, MCM force must be reconfigured for worldwide operations. Mines are cost-effective weapons that can serve as an important force multiplier, but humanitarian and political considerations mandate that they not be deployed without sufficient control to ensure the limitation of collateral damage and injuries to third parties. A VISION OF FUTURE MCM FORCES It is anticipated that future battle groups will have organic MCM capability in the form of air, surface, and underwater platforms. The air platforms will likely be helicopters with improved, lighter MCM sonars, LIDAR devices, and
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare possibly supercavitating projectile mine killers. The surface platforms will likely include remotely controlled, unmanned, small, stable, long-endurance platforms, possibly based on small waterplane twin hull (SWATH) technology, towing sonars and other MCM devices. Underwater platforms will include swim-ahead UUVs with mine detection, classification, and neutralization capability. The MCM force of the future will likely be composed of smaller and more numerous vessels, transported by a mother ship, that can be rapidly deployed worldwide to keep shipping lanes open and harbors cleared. Such a force will be designed to counter an arsenal of new mines with remote control, networking, and selective targeting capability. It is unlikely that a single technology or system will emerge that alone will render the mine threat harmless. It is expected that future mine countermeasures will continue to consist of a number of systems ranging from the elemental to the highly sophisticated, each essential to a balanced capability to deal with the overall mine threat. Five main thrust areas must be pursued in order to meet the MCM challenge of the future: Robust intelligence, surveillance, and reconnaissance capability. Integration of MCM as a capability organic to the battle force. This includes specific MCM capability resident on selected battle group combatants and expanded MCM capabilities provided by MCM ships and helicopters that are transported with the battle group or the amphibious ready group (ARG). Technologies that address primarily the very hostile mine detection and neutralization environment of the surf zone and the craft landing zone. These generally fall into the brute force category. Advanced networked sensor and weapon systems consisting of controllable mines and including autonomous and semi-autonomous detection devices. Application of cost-effective mine shock hardening and acoustic and magnetic signature reduction technologies in all new construction ships. The following paragraphs expand on these thrusts. Intelligence, Surveillance, and Reconnaissance Accurate and complete intelligence, surveillance, and reconnaissance is the most effective means of enhancing the capability of MCM forces. ISR enhances the efficiency of MCM operations by reducing the threat to a minimum prior to the initiation of sweeping, hunting, and neutralization activities. ISR was the highest-priority recommendation of the Naval Studies Board report Mine Countermeasures Technology.3 The importance and priority of that recommendation are reinforced and restated by the present study. 3 Naval Studies Board. 1992-1993. Mine Countermeasures Technology, Vol. I-IV, National Academy Press, Washington, D.C.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare The recent increased attention to surveillance through such programs as the Radiant Clear Program, which seeks to develop a capability for littoral remote sensing, and the emphasis on reconnaissance-related research and development signal a possible turning point that, if pursued further, could provide the quality of intelligence that will become an effective force multiplier. It is to be emphasized that for this gain to be realized, priorities on the use of surveillance assets must be set now and the infrastructure installed for collection, analysis, and timely display of the resulting information. Intelligence requirements include a comprehensive database of world mines describing capabilities and characteristics, detection and triggering technologies, size and locations of stockpiles, manufacturing facilities, transportation routes, mine laying facilities and capabilities, and likely areas of deployment. Further, foreign manufacture and sale should be monitored, much like what is now done with respect to submarines. A robust ISR effort should include the acquisition and examination of foreign mines. This is a relatively inexpensive effort that holds promise for significant payoff, but one that has been poorly pursued in the past. An effective factory-to-seabed ISR system should include a full set of ISR methods, including surveillance by satellite, atmospheric manned and unmanned vehicles, submarines, human intelligence, and special forces. Such a system would enable the preparation of detailed a priori plans and provide real-time support for the movement of forces. Ultimately, it could provide the option of interdicting mines prior to planting, or avoiding mined areas entirely, or failing both, it will allow MCM forces to be concentrated on mined areas of known characteristics. Battle Group and Task Force Organic MCM In a future where conflicts are likely to arise suddenly and unexpectedly, it will be necessary for naval forces to be capable of reacting swiftly and independently. Since the geographical locales of possible conflict are so widely dispersed, it will be impractical to create forward-based MCM forces. Thus, the dedicated MCM force the Navy has now must be transformed into a set of MCM assets carried by, or organic to, battle groups and task forces. The latter will be required to provide self-protection and deliver MCM capabilities to theater along with Navy presence. A battle group MCM force might consist of a specially configured support ship with MCM command and control capability (C4I), and the ability to transport and maintain small MCM ships and helicopters. MCM C4I capability should include links to other task force elements, access to environmental sensors, including those deployed on satellites, as well as other data sources and decision aids to support tactical MCM. Provision should be made for special signals such as those required to implement remote mine neutralization on command. New hull concepts permit the design of smaller vessels capable of operating effec-
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare TABLE 2.1 Notional Small MCM Vessel and Support Ship Small MCM Ship Design Possible Sensors Support Ship Characteristics Length: 36 feet Displacement: 26 tons Payload: 4 tons Low signature 24 knots Gas turbine/electric drive Active EM cancellation SWATH hull design Sea state 4 capable Modular (to allow air transport) Unmanned 100 n. mi. endurance Forward looking, low-grazing-angle LIDAR and sonar Expendable mine neutralization GPS navigation Remote optical system VDS sonar Acoustic pulse power Laser line scanner C2-RF/fiber Optic, mammal, bioacoustic adjunct Deployable UUV Size: up to LSD dimensions Payload up to 2-10 MCM ships 2-10 MCM helicopters JMCIS compatible Battle group speed: 28 knots Number: as appropriate for size and operational concept tively in sea state 4 conditions, and advances in lightweight sonars, synthetic aperture techniques, and lighter sweep gear will enable these smaller vessels to provide the functional capability of today's larger ships. Table 2.1 outlines a possible design. Technology currently under development or likely to become available in the near future will allow battle groups to carry light helicopters that are capable of night operations and able to carry modular payloads including advanced electro-optic mine hunting systems, lightweight acoustic and mechanical sweeps, and mine neutralizers launched directly from the helicopter, such as gun-fired high-speed supercavitating projectiles. These will be augmented by off-board, remotely controlled, autonomous or semi-autonomous vehicles, with acoustic and other sensors and systems for mine detection, classification, and neutralization and with the endurance and ability to search ahead of the battle group at moderate transit speeds up to 15 knots. Undersea variants will provide covert reconnaissance capabilities. Brute Force Mine and Obstacle Clearance There will be situations in which MCM operations that deal with one mine at a time cannot be conducted because of the density of the threat and lack of time or because normal MCM operations are slowed or ineffective due to the harshness of the environment, stealthiness of mines, or presence of buried mines. In these cases brute force methods of breaching will be required. This is likely to be especially true in the surf zone (SZ), the craft landing zone (CLZ), and the beach regions-where a dramatic increase in the density of mines and obstacles may be expected. Brute force breaching methods may require complex engineering,
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare precise timing and fusing of explosives, unique chemical systems, accurate navigation, and high reliability. There are two promising approaches that warrant further development: (1) precise time-space control of explosives that will remove mines and obstacles, and (2) the placement of a foam causeway over a mine field. The Naval Studies Board Mine Countermeasures Technology4 study recommended a concept in which precisely positioned (to GPS-level accuracy), impact-buried bomb explosives timed to go off nearly simultaneously, forming an equivalent buried line charge, are used to excavate a channel through the SZ, the CLZ, and through the minefield up the beach. See Appendix F for an explanation of the efficacy of simultaneous detonation for explosive channel excavation. Mines and obstacles are effectively removed from the deepened channel, which eventually fills with water, by the excavation process. The phenomenology, scaled dimensions, and removal of mines and obstacles have been confirmed by a scaled experiment conducted jointly at the UK Weston Supermare Shallow Water Test Range by the Naval Surface Warfare Center (NSWC) at White Oak, Maryland (now NSWC at Indian Head, Maryland).5 Independently, the Lawrence Livermore National Laboratory's (LLNL's) Defense Studies Group has proposed similar concepts using bombs available from inventory, with special fusing. Results of the NSWC experiment are in agreement with calculations performed by NSWC and LLNL. If, as discussed in Volume 5: Weapons of this series, advanced explosives could be successfully developed in the 2000-2035 time frame, with several times current explosive fill effectiveness, a wider range of options for delivery and use of controlled space-time explosive patterns might become possible. The panel recommends that investigations and appropriately scaled experiments continue on channel excavation phenomenology and explosive placement sensitivity. Some of the needed data can probably be obtained using high-g centrifuges. An overall modeling capability should be achievable to enable tradeoffs of explosive weight, spacing, penetration depth, and channel width for different delivery and fusing options, threats, and environmental conditions. Research conducted at Sandia National Laboratories on petrochemical-based binary materials has led to the development of quick-setting rigid polyurethane foam (RPF). The chemicals, transportable as liquids, when mixed and exposed to air form a relatively tough, quick-setting rigid structure that floats on the surface. The volume expansion between the component liquids and the final rigid foam is 4 Naval Studies Board. 1992-1993. Mine Countermeasures Technology, Vol. I-IV, National Academy Press, Washington, D.C. 5 Furr, W., R. McKeown, and L. Taylor. 1996. "Mine and Obstacle Breaching by Explosive Evacuation in the Surf and Beach Zones," Technology and the Mine Problem Symposium, Monterey, Calif., November 18-21.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare a factor of 20 to 60, and the resulting structure has a bearing strength sufficient to withstand the repeated passage of heavy vehicles, including tanks. Tests indicate that the foam can absorb some degree of explosive blast energy, can withstand puncture by bullets without significant structural weakening, and poses no extraordinary fire hazard. Tests also indicate that foam will incapacitate the sensors on pressure and tilt-wand mines if they are immobilized in the foam, will provide a standoff for magnetic mines, and will reduce the profile presented by obstacles to assault traffic. As important as these results are, more experimentation under actual operational conditions is needed to fully evaluate the potential of foam. Other brute force systems offer promise and may be worthy of further development. Some concepts such as guinea pig ships and barges have been used operationally in the past, for example, in Haiphong harbor, during the Vietnam conflict. In this case, the ship was not employed as a sweep platform, although it was designed as one, but rather was used to prove that the United States had indeed cleared the harbor of mines. The same concept with improved automation, remotely controlled unmanned platforms, and precise navigation remains an attractive a means to prove that a safe passage has been cleared through a minefield. Autonomous Networked Undersea Systems Advances in sensors, signal processing, and computational power will enable the development of autonomous and semi-autonomous systems. In support of ISR, networked multiple undersea surveillance systems using small, autonomous undersea vehicles have significant potential for providing a covert mine surveillance, detection, and neutralization capability. These systems could be smart systems, with a hierarchy of intelligence and capability, intervehicle communications within the water column, and communications to remote command and control nodes. They could operate autonomously, reporting only when interrogated or as programmed. The development of communications technology, acoustic and otherwise, will be an essential enabler for this type of system. Data transfer rates beyond those now possible will be required. Accurate navigation also will be required. Additionally, autonomous vehicle systems could be combined with other distributed sensor systems deployed either simultaneously or in sequence. Vehicle technology pursued in past UUV research programs forms the basis for future efforts. Multiple vehicle approaches, which offer the efficiency of systems operating in parallel, could include stealthy surface vehicles and bottom crawling devices. Specific requirements, concepts of integrated operations, and possible countermeasures must be investigated, however, to more clearly define the viability of any single design. Such a system can be a force multiplier capable of detecting, classifying, and neutralizing mines either as a stand-alone system or incorporated as an integral part of a larger networked system. On the offensive
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare side, the same technology can enable the development of networked autonomous weapons, including mines and minefields, with fail-safe remote control and command links and selective targeting. Such an offensive system can be a force multiplier by denying large areas of the ocean to enemy vessels without posing any danger to friendly forces and noncombatants and without tying up valuable Navy ships or putting personnel in harm's way. Magnetic and Acoustic Signature Reduction and Platform Shock Hardening Mine fuses rely on sensing the magnetic and acoustic signatures of ships and submarines for detection, classification, and initiation of their attack mechanism. Expected technology advances in mine fuses will yield improved sensitivity and noise rejection. Unless a commensurate effort is made to reduce the signatures of current and future platforms, their vulnerability to mines will increase in the future. Signature reduction measures that utilize both passive and active signature reduction techniques can be developed and implemented. Enabling technologies include sound- and vibration-absorbing materials and isolation techniques, active vibration and acoustic signature control, closed-loop adaptive magnetic degaussing systems, and cathodic current reduction. Even with the most aggressive campaign to reduce signatures, there remains the possibility of triggering a mine. Indeed, a simple contact mine is not impaired by target signature reduction. Given this situation, especially as organic concepts of MCM are implemented wherein more ships will be placed in the vicinity of mines and minefields, it is essential that these platforms be shock resistant. EMERGING ENABLING TECHNOLOGIES Although the priority areas cited above will form a foundation for a robust future MCM capability, they must be bolstered by continued support for research in promising emerging technologies. The capability that the Navy is able to field in the future depends on research undertaken today. None of the required systems or technologies will be developed without a strong underlying R&D program. Lighter-weight sweeps with wider-swath, higher-resolution sonars; synthetic aperture sonars; active (laser) and passive optical systems; expendable neutralization methods; sonars based on biosonars (mammals) capable of detecting buried mines; and pulsed-power devices and biosensors will not be realized without a commitment to R&D. UUVs with intelligent control, long range, and endurance; networked underwater sensors; rigid foam causeways; small and stable surface platforms; and high-data-rate acoustic communications will not emerge without concomitant research. Optimum employment of systems and sensors based on the characteristics of the highly variable littoral environment will not occur without ocean physics, sedimentology, and meteorological research. The
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare full benefits of modeling and simulation in the design of sensors and systems and in developing the most effective operational employment of the full spectrum of MCM capabilities will not be realized without an underlying research base. TOWARD A BALANCED MCM FORCE: THE NEAR TERM On the path to the MCM capabilities of 2035, the panel believes that the near-term concepts, technologies, and systems should, when integrated with existing capability, provide the Navy-Marine Corps team with the ability to clear mines in stride by the year 2005 or earlier, at reasonable cost. The panel kept several objectives in mind when evaluating these concepts and technologies. The first objective is to pare the mine threat in a given campaign to the minimum that must be dealt with effectively as a function of three phases of the campaign—the most critical phase in which the first forces are inserted, the second phase when the heavy manpower and logistics must be landed, and the third phase when maximum sea-based traffic is expected. From the MCM standpoint, the major distinction between the phases involves the channel widths to be cleared and the time to do so. The second objective is to achieve a balanced and flexible MCM system capable of countering the full spectrum of mine threats. The third and final objective is to select concepts that will add clearance speed and efficiency to the MCM system at minimal costs and that can be implemented in the near-term future. Intelligence, Surveillance, and Reconnaissance Intelligence, surveillance, and reconnaissance, considered as a whole, was the highest-priority recommendation of the Naval Studies Board Mine Countermeasures Technology report.6 A continuous, robust ISR effort targeted at potential mine threats can greatly enhance the efficiency of MCM operations by enabling accurate characterization of the threat prior to initiation of sweeping, hunting, and neutralization activities. Many of the assets necessary for the intelligence and surveillance functions already are in place, and much of the technology development necessary for the reconnaissance function has been, and will continue to be, supported by entities other than the Navy. Intelligence can provide information on the type, size, and location of an adversary's mine stockpile, the method and route of transportation to mine layers, platforms allocated to mine laying duty, and the adversary's plans for mine defenses. Surveillance by satellite, manned and unmanned aerial vehicles, submarines, human intelligence, and special forces can track mine laying activity from bunker to beach or sea bottom. Reconnaissance, preferably covert, by 6 Naval Studies Board. 1992-1993. Mine Countermeasures Technology, Vol. I-IV, National Academy Press, Washington, D.C.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare two outer electrodes (one at each end) would carry current, thereby establishing an electric field, which would be monitored by the inner non-current-carrying electrodes. The upper surface of the array would be insulated to prevent interference by surface waves. Metallic mines will register as an increase in conductivity, and nonmetallic mines will register as a nonconducting anomaly within the field. Detected anomalies would be correlated and analyzed by a small computer. Although false contacts may be a problem in some areas since the method is unlikely to allow positive classification, in the absence of any alternative for swimmer detection of buried mines together with the capability to detect both metallic and nonmetallic mines, the electrical resistivity method may provide a useful capability. The electrode array could also be mounted on a UUV. Biosensors: Mammal Sonars There are many ways of reducing the signature of a mine to make it less detectable, such as using materials and shapes that blend in with the environment, constructing it of nonmagnetic materials, or designing it to have a low acoustic cross section. Existing mine hunting sonars have a very difficult task detecting reduced-signature mines, and in the short term, the Navy may be forced to rely on sweeping and brute force methods when such mines are known to be deployed. However, in the long term, future detection systems are expected to counter this problem. The reason for optimism lies in the performance of biological sonars, such as those of dolphins. These mammals are able to detect prey by sonar, even small fish that have much lower signatures than any mine and can conceal themselves by burrowing in the sediment. In many ways, they outperform hardware. They are the most (perhaps only) effective system available for finding buried mines. They are effective in locating, identifying, tagging, and charge placement. Unfortunately, however, their range (>20 km) and endurance system are limited, they are sensitive to temperature, they have stringent on-site handling requirements, and they pose difficult logistical demands. It may be possible for potential adversaries to engineer mine signatures in such a way as to make detection by marine mammals more difficult, but given the limited use of mammal-based mine hunting systems, it appears unlikely that any nation will go to this expense in the near-term. All of these shortcomings could be overcome if the features of mammal sonars were incorporated into hardware. Since 1959 there have been a number of small research programs with this objective, but little has found its way into practice. For example, mammal sonars are known to adapt, presumably in some optimal sense, to the environment in which they operate. They change pulse types, durations, and frequencies. They use two ears, and they approach targets and view them from several aspects. These notions have had only elemental incorporation into sonar system design. It is not unreasonable to postulate a man-made sonar with the same capabili-
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare ties as a mammal sonar, especially with the growing understanding of cognitive processes and the development of systems such as neural networks that mimic them. The payoff in vastly improved sensor performance is so great that research aimed at revealing the mechanisms of biosonars with an aim toward emulating them should be given high priority. Active Electromagnetic Mine Detection Pulsed electromagnetic induction is a methodology that has been employed successfully in geophysical prospecting for conductive ore bodies. It is an active electromagnetic technique whereby a primary magnetic field is used to induce currents in nearby conductors. The currents decay because of resistive losses, creating secondary magnetic fields that are detected above Earth's surface. The rate of decay of the secondary field contains information about the size, conductivity, and magnetic permeability of the object. Although the application of this approach to mine and submarine detection was investigated by the Naval Ordnance Laboratory in the 1950s, recently a new processing technique using holographic imaging has shown considerable promise. It is recommended that progress with this technology be closely monitored and applied to MCM systems as appropriate. OFFENSIVE MINING The Case for Offensive Mining At present, a segment of the naval community questions whether, in the high-technology weapon environment we are now entering, the Navy will have a need for mines in the future. Yet there has not been a time since the 1930s during which the Navy has been more in need of mines to leverage a reduced fleet with expanded global responsibilities. First there is the deterrent value of a credible mine stockpile and the ability to deliver it—covertly, if necessary. The deterrent value of that stockpile will be measured by the sophistication of its content and the adversary's uncertainty of being able to counter the mine types it contains. There is also the need to be able to supply our allies with effective mines to provide for their own defense or to slow down an assault until U.S. forces can arrive. Taiwan and South Korea come to mind, although both have the technical ability to design superior mines on their own. Perhaps the Navy's greatest need for mines in the present environment is for effective blockade of strategic ports and straits without the need for exposing lives and high-value targets to defensive action. With reductions in force levels there is justifiable concern on the part of both the Navy and the Marine Corps regarding the ability to handle two simultaneous medium-level conflicts. In those scenarios in which the aggressor's ambitions are based in significant part
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare on the use of naval forces, mines could be useful in stopping or seriously delaying such aggressive action until additional force can be brought to bear. The growing dependence on submarines around the world and the slow but steady increase in the proficiency of their crews signal a serious problem for the Navy and Marine Corps team in any future attempt to project power against the land. Advanced mine designs capable of protecting the flanks of an amphibious assault force from submarines will significantly leverage the available combatants. Such mines could be equipped for preset explosive self-destruction when their job is done. Near-term Needs and Recommendations Sustaining a Mine Design Team One of the many casualties of the post-Cold War downsizing has been the mine design capability so long resident at the old Naval Ordnance Laboratory at White Oak, Maryland. The White Oak team, in which resided the expertise and corporate memory accumulated since World War II, has been reduced to token representation of mine design specialists and supporting documentation at the Coastal Systems Station in Panama City, Florida. The Navy and Marine Corps will need a small mine design team composed of the most highly qualified scientists and engineers it can attract to the job in order to (1) assist the technical intelligence community in interpreting new, and often fragmented intelligence data; (2) analyze and help develop countermeasures to foreign mines; (3) prevent technological surprise; (4) conduct research from which the Navy can select its future mines; and (5) serve as a Red Team for the MCM research and development community. The panel strongly recommends that such a team be built around the token element now resident at the Coastal Systems Station. Remote Command and Control With the placement accuracy made available by GPS navigation, it is now possible to lay offensive minefields in order to prevent defensive mining and yet leave unmined channels for use by our own forces. This technique has long been suggested but, due to navigational uncertainties, considered too dangerous to our own forces to be implemented. The alternative, of course, would be to develop a remote command and control of mines feature of such reliability that our own forces would pass over a command-off minefield with confidence. Commanders, particularly those of high-value ships, have been reluctant to accept this technology over the past 25 years. However, there appears to have been no hesitation in passing over the controlled minefields used to protect Allied harbors in World Wars I and II or the one used by Norway throughout much of the Cold War. The
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare difference between the old and trusted system and the yet-to-be-trusted new system, besides vastly improved electronics in the latter case, is that the old system had a man in the command-on-command-off loop. Littoral Sea Mine To fill and improve on the void to be left by the Mk 56, the Navy should seriously pursue a littoral sea mine (LSM). A mission needs statement currently exists for such a mine, and an advanced technology demonstration (ATD) has been proposed by the Navy and industry. The prototype LSM will consist of a three primary subsystems: (1) a target detection system that leverages ongoing sensor technology demonstration efforts; (2) a mobile homing warhead that uses the lightweight hybrid torpedo currently being developed; and (3) a subsystem that leverages ONR's deployable autonomous distributed system technologies. The target detection system will provide the capability to detect, localize, and track targets in the littoral environment to within the lethal zone of the lightweight hybrid torpedo. It will consist of a multi-influence passive detection subsystem and an active target verification subsystem. The passive detection subsystem will acquire and process target signature data and initiate the transition to the active acoustic verification mode. The active sonar will transmit low probability of target alertment pulses to make multiple range and bearing determinations until a target track converges with sufficient quality to verify that the target is within the mine's lethal zone. The target detection system will then activate the mobile homing warhead, pass targeting information to the vehicle, and prepare it for launch. The primary function of the mobile homing warhead is to deliver a bulk charge warhead from the mine's deployed position to within the mission abort damage range of the target and to detonate the warhead at the appropriate time. Using the lightweight hybrid torpedo as the mobile homing warhead payload utilizes the speed, maneuverability, and zone-homing performance of the torpedo. This will increase the mine's lethal-zone-coverage capability over that of the Mk-56 mine. Also, since the lightweight hybrid torpedo can be vectored in azimuth from a vertical launch, which was not possible with the encapsulated torpedo (CAPTOR) mine using the Mk 46 Mod 4/6 torpedo, a single mobile homing torpedo can cover many target volumes. A RECO subsystem will provide the capability to control an LSM field from a surface or submarine platform. The Marines and the Modern Homing Mine (HOMINE) The Marine Corps depends largely on the Army for its land mines and the countermeasures to such mines, and for that reason, as noted in the Preface, this report deals mainly with sea mines and mines in the surf and craft landing zones. It appears, however, that evolving Marine Corps strategy and tactics for land
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare combat (i.e., many light, small units, widely spread, very lethal, and highly maneuverable) will generate requirements for both land mine and land mine countermeasures that differ from those of the Army. In the late 1960s and early 1970s, the Army developed to the prototype stage a distributed sensor antitank minefield called HOMINE. The sensors were small, inexpensive, easily scatterable devices consisting of either a pressure or a magnetic sensor and a simple radio transmitter. The radio signal was coded, and all sensors for a given kill system had the same code. When approached (or run over in the case of the pressure sensor) by a tank or armored vehicle the radio transmitter emitted a single, coded burst. The radio burst gave no indication as to which sensor had activated or where within the field the target was, but this was not needed. The multiple-shot kill system was concealed centrally within the sensor field, or centered along its periphery, and consisted of a short grain solid rocket motor, an IR sensor, a warhead, and limited control surfaces. On receiving a signal from one of the sensors the rocket boosted the kill system such that it coasted to a stop at an altitude of 1,000 feet, turned over, detected the target with its IR sensor, and glided to impact. For reasons unknown to the panel, HOMINE was dropped before reaching service use. It may be wise, however, for the Marines to examine the HOMINE concept with an eye toward further miniaturizing both the sensor and the kill system using modern technology. A variety of such broad-coverage systems that place little weight on the logistic burden is possible. Far-term Needs and Recommendations Mine Delivery Any consideration of the future emphasis that should be placed on mines is incomplete without considering the deliverability of such weapons. Today, virtually all of our mines are delivered by either submarines or aircraft. U.S. forces have no surface ships uniquely configured for mine laying, and for a very good reason. The advantage of such ships diminished as the transition was made from the cumbersome Mk-6 type moored mines that had to be trundled around on their own wheels to the more easily handled bottom influence mines and more efficiently designed moored mines. Most modern mines can be laid by practically any surface ship, as demonstrated by the former Soviet Union and by such countries as North Korea, Iran, and Iraq. The Navy's lack of attention to surface ship mine laying has been due primarily to the fact that the emphasis has been on offensive rather than defensive mining, where the advantage of the surface ship and its delivery capacity are greater. Let us assume, then, that the Navy's emphasis in mine laying will continue to be on the submarine and aircraft and that the surface ship can be pressed into service without undue modification. The main advances in mine deliverability will come from the mines them-
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare selves, not from new aircraft and submarine designs. Specifically, advances will come from the continued miniaturization of electronics and from the introduction of explosives with greater energy yield. As an example, the old Mk-55 mine was 21 inches in diameter and 114.6 inches long (the instrument section took up about 20 percent of this length), weighed 2,196.5 pounds, and carried a 1,270-pound explosive charge. Using modern electronics and case material and merely doubling explosive energy yield (considered attainable during the projection period of this study) would produce a mine with improved performance and equivalent destructive capacity, but that would be only around 45 inches in length and would weigh about 700 pounds. Thus, it appears possible, without heroic efforts, to cut the mine delivery sortie requirements of both submarines and aircraft by more than half. Also, if the tubes on a retiring SSBN could be used for mine laying (now being considered for the Tomahawk missile) each D-5 tube could carry roughly 35 mines, or a total of 840. Such a size and weight reduction also introduces the possibility of the delivery of sea mines by rocket, which is now done with land mines. Networked, Controllable Minefield With the projected advances in sensors, processing, and communications technologies, an advanced concept of an intelligent minefield appears feasible for the future generation of sea mines. Envisioned is a networked laydown of individual mines that can communicate to pass information and data and to utilize effectively the distributed sensor information they collectively obtain. In addition to the increased performance obtainable from distributed surveillance, the minefield could be designed with sufficient intelligence to achieve remote failsafe command and control and selective targeting. This attribute could reduce the current aversion to mining conceived as a distribution of indiscriminate lethal weapons. The networked minefield concept includes the notion of separated detection or targeting sensors and attack weapons. This would permit the cost-effective laydown of separate detection nodes and connected weapons tailored to the requirements of the local environment and threat picture. The technology enablers for multi-influence detection sensors—distributed processing, networked communications, intelligent control architectures, and lethal attack mechanisms—should be pursued. The networked, controllable minefield has the potential to mitigate concerns regarding indiscriminate mining and has the flexibility for tailored deployment that can provide significant cost savings. CROSS-CUTTING TECHNOLOGIES This section deals with several technologies that are applicable to a wide spectrum of mine warfare and mine countermeasures issues.
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare Modeling and Simulation for Mine Warfare The Navy and Marine Corps, as well as the other Services and DOD, are becoming increasingly dependent on the rapidly expanding field for the design of weapons and their countermeasures, for their evaluation, for the development of tactics and doctrine, for training, and as an aid in procurement decisions. This subject area is comprehensively addressed by the Panel on Modeling and Simulation in Technology for the United States Navy and Marine Corps, 2000-2035: Becoming a -Century Force, Volume 9: Modeling and Simulation. As with any application of modeling and simulation, modeling and simulation aids for mine warfare should rest on a sound theoretical basis. Unfortunately, developing such a basis is not straight-forward because the underlying mathematics are difficult and require an understanding of probabilistic dependencies. In the past, workers have developed models for estimating the effects of minefields or mine countermeasures that, although seemingly sound, have in fact been highly misleading (see Appendix J, ''Probabilistic Dependencies in Combat Models," in Volume 9: Modeling and Simulation). Configural Theory Configural theory, developed by a small research group working under contract for the Navy, is a mathematical theory that quantifies the relationships between the behavior of weapons in use in combat and their individual characteristics. Its principal purpose is to provide concepts and mathematical relationships to improve understanding of the behavior of weapons in combat and of their combat effectiveness. Its name is derived from its central concept, configuration, which is the mathematical expression of the fact that the disposition in space and time of the targets and weapons of the attacker and defender influences the outcome of the engagement and the combat effectiveness of those weapons. Among the conclusions from the research17,18 conducted thus far are the following: (1) nonconfigural representation of target-weapon encounters may be suffi- 17 Horrigan, Timothy, J. 1992. "The Configuration Problem and Challenges for Aggregation," pp. 102-153 in Proceedings of the Conference on Variable-Resolution Modeling, Washington, D.C., May 5-6, CF-103-DARPA, Paul K. Davis and Richard Hillestad, eds., National Defense Research Institute, RAND Corporation, Santa Monica, Calif. 18 Horrigan defines configural theory as "a mathematical theory for quantifying the relationships between the behavior of weapons in use in combat and their individual characteristics. Its principal purpose is to provide concepts and mathematical relationships to improve our understanding both of weapon behavior in combat and of combat effectiveness. Its name is derived from its central concept, configuration, which is the mathematical expression of the fact that the disposition in space and time of the targets and weapons of the attacker and the defender is inseparable from the outcome of the engagement and the combat effectiveness of those weapons."
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare cient to invalidate a model or simulation; (2) Lanchester-theory-based representations, deterministic or stochastic, are generally nonconfigural; (3) the conception of weapons effectiveness and the derivative mathematical models, particularly those based on initial threat and free encounter (independent event), may be inappropriate; and (4) nonconfigural assessments may, in some instances, significantly overstate weapon effectiveness and make less effective weapons appear preferable to more effective weapons. Configural theory is an approach to mine warfare analysis that permits development of a comprehensive and reasonably correct model system encompassing relevant characteristics and interactions, including spatial, temporal, and entity-specific relationships. It has generated a new family of meaningful measures of effectiveness. Simpler analytical models that form the basis of tactical decision aids currently in use for mine warfare applications do not properly account for probabilistic dependencies and entity-specific relationships (see, for example, Appendix J in Volume 9: Modeling and Simulation in this nine-volume series). Not surprisingly, the application of configural theory requires greater rigor and time than nonconfigural models, but its use would enable a significantly better understanding of mine warfare and thus help to optimize the allocation and application of mine warfare resources. New Modeling and Simulation Tools Advances in computer memory, processing power, networking, and visualization have dramatically improved modeling and simulation capabilities. These technologies offer revolutionary advances in the simulation of military operations and high-detail interactive representations for design and manufacture. Organizations involved with traditional exercises, training simulators, computer simulations, war games, system design, and test and evaluation are beginning to experiment with these new tools. Two key issues are how much to invest and where. A key concern is verification, validation, and accreditation (VV&A). The key benefits of the new modeling and simulation technologies are bringing the operator into the simulation and providing necessary linkages such as those between designers and operators, different members of a unit, different units of a force, and so forth. For the MCM community, four key applications are possible: (1) integrating MCM into Navy and Joint Force planning for acquisition and operations; (2) improved tactical development and training despite geographic separation of the principal MCM forces from the fleet and dispersal of the reserve component; (3) the timely development of appropriate systems to counter a threat that is rapidly changing, increasingly sophisticated, affordable to all potential enemies, and likely to be encountered in difficult coastal environments; and (4) improved understanding of the environments relevant to MCM in the littorals. The key challenges to realizing the promise of the new modeling and simulation tools for MCM are the selection of appropriate focal points for investment,
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare adapting emerging technologies to these focal points, acquiring supporting databases, and designing a VV&A program that will build confidence in the tools and establish their effectiveness. Environmental Characterization The effectiveness of MCM sensors is critically dependent on the environment in which they operate. LIDARs, for example, are ineffective in dust storms. Sonars operate differently in fresh and saline waters or in regions with hard and soft bottoms. Knowing the environment in which the sensor is operating and understanding its effects on the sensor can make significant differences in levels of performance. MCM forces need to be provided with a level of environmental prediction and sensing and an ability to optimally tune their systems, not unlike those provided to ASW forces. Adaptive sensors, which automatically sense their most effective parameters, can provide the needed in situ data. In the case of sonar, for example, the system itself can be used to measure its surrounding environment-sound speed profile, bottom backscatter, surface roughness, bubble attenuation, and so on-and automatically select an optimal operating frequency, beam pattern and signal type. Global Positioning System To neutralize the mine threat in minimum time, with minimum assets and effort, will require that all surface and air MCM platforms and those platforms transiting cleared channels be equipped with GPS receivers, that crews be thoroughly trained and practiced in their use, and that all charts and maps be digitized using GPS coordinates. The spatial coordination required by the MCM-amphibious assault-sea-based support element, from crisis initiation to last mine cleared, is demanding, and can be achieved only if GPS precision is available to all components. Without it, the goal of rapid conflict resolution with minimum casualties will not be attained. The panel urges the Navy and Marine Corps to equip all relevant platforms, subject their crews to extensive training, and ensure the conversion of maps and charts. MCM Night Operations The MCM platforms available in any future conflict could effectively be doubled simply by adding the capability to carry out night operations. The panel is aware of the principal reasons such operations have not already become standard practice. AMCM helicopters are not equipped with artificial horizons and night vision equipment, and while in tow, they fly in a dangerous part of the flight envelope. MCM surface ships are justifiably concerned about navigation in close proximity to the minefield and about the possibility of floating mines. The
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare provision of artificial horizons and night vision equipment has a straightforward fix, and systems have been recommended above for dealing with the floating mine problem. The question of night flying in tow with acceptable safety given proper equipment, the panel leaves to helicopter pilots to judge. Otherwise, the panel sees no reason why the MCM force should not adopt—even eventually prefer, all things considered—night operations. This is but another way of leveraging the force. RECOMMENDATIONS Mine warfare continues to be a technological challenge because of the proliferation of mines and mine technology. However, the Navy can take steps now that will provide a robust countermine capability within the horizon of this study (2035), enabling the United States to execute national policy worldwide. Recommendations arising from this study, and detailed in the report, are summarized below. Highest-level Recommendations Near Term Implement a factory-to-seabed intelligence, surveillance, and reconnaissance capability, using a full set of ISR methods, including surveillance by satellite, atmospheric and undersea manned and unmanned vehicles, submarines, human intelligence assets, and special forces. Develop technologies that will provide naval forces with organic MCM capability, including helicopter-compatible sweeping and hunting equipment, remotely operated off-board surface or UUV sensors, and on-board MCM sonars. Aggressively pursue the development of so-called brute force technologies that will neutralize mines and obstacles in the very shallow water zone, the surf zone, and the craft landing zone. Far Term Develop technologies for advanced networked sensor and weapon systems consisting of the following: Autonomous and semi-autonomous networked undersea systems using small, autonomous undersea vehicles, bottom-crawling variants, and fixed sensors for far-forward covert MCM; and Controllable mines with remote fail-safe command and control (C2) and selective targeting. Develop next-generation MCM ships as small platforms capable of sea state 4 operation, carried by a mother ship capable of battle group speeds. De-
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Technology for the United States Navy and Marine Corps, 2000–2035: Becoming a 21st-Century Force, Volume 7 Undersea Warfare velop the lightweight hunting and sweeping technologies required for these smaller units. Apply reasonable mine shock hardening and effective acoustic and magnetic signature reduction technologies to all new-construction ships. Recommendations for Follow-on Action Build an expendable mine neutralization system capable of being used, with minimal adjustment, by AMCM helicopters, by the MCM-1 and MHC-51 MCM ships, and by small MCM surface craft yet to be introduced. Continue research to reveal the acoustic detection and classification methods used by dolphins. Emulate this capability to radically improve sonar sensor performance. Continue to develop synthetic aperture sonar technologies to significantly improve the location and classification of mines from a safe distance. Establish a research and demonstration program for rigid polyurethane foam causeway concepts. Support the development of mechanical methods-ploughs, chains, and power blades. Develop guinea pig ships and barges to verify clear paths to the beach. Consider unmanned, precisely navigated, hardened platforms. Specifically test precision bombing techniques for removal of mines in shallow water and in the surf and craft landing zones. Investigate this technique in light of newly developing higher-yield explosives. Support further development of explosive MCM methods such as net and line charges. Support research on pulse power technologies; this should include demonstration of concept and performance measurements. Take full advantage of new modeling and simulation tools with initial focus on fleet-level applications, training, exercises, decision aids, and tactical development. Reinvigorate the mine design team to provide effective offensive mining concepts and exploit threat mines. Continue to develop technologies to improve environmental characterization for improved sensor performance, including through-the-sensor environmental measurement methods. Provide systems and training that will allow the fleet to conduct night MCM operations.
Representative terms from entire chapter: