TRANSFORMING THE UNDERSEA BATTLESPACE

By NILS SJOSTROM

NUWC Builds an Architecture of Combat Excellence.

Capt. Nils Sjostrom, USN (Ret.), a career submariner, is former commanding officer of the nuclear-powered attack submarine USS Groton and commander, Submarine Squadron Two. He has been employed at the Naval Undersea Warfare Center Division of the Naval Sea Systems Command (NAVSEA) in Newport, R.I., since 1999, on projects related to the development of undersea warfare capabilities and initiatives.

One of the goals of the NUWC research program is to capitalize on recent advances in technology to develop new systems and sensors that will enable the Navy's future undersea platforms, manned or unmanned, to dominate the USW battlespace and link with shipboard and airborne platforms to form network-centric battle groups capable of ensuring U.S. maritime dominance in the littoral environment almost anywhere in the world.

The collapse of the USSR has prompted the most dramatic changes in naval undersea warfare since the buildup after World War II and the start of the Cold War. Addressing the numerous bluewater challenges posed by the Soviet Navy in the early phases of the Cold War required many important shifts in the U.S. Navy's operational concepts and organizational structure, as well as the incorporation of new technologies to effect transformational capabilities. The end of the Cold War has shifted the U.S. Navy's bluewater focus to the littorals and to a broad spectrum of new threats to national security. The forward-presence capabilities of the U.S. Navy, always a critical part of America's defense posture, remain essential.

The adjustment to the new operational challenges occurred during two periods of significant change. The first period, in the late 1980s and early 1990s, was precipitated by rapid advances in commercial off-the-shelf processing hardware. Capitalizing on the new technologies available and incorporating commercial industry standards allowed the development and delivery of open-architecture warfare systems that could readily accommodate rapidly improving commercial hardware and software.

The Algorithms of Future Capability

These changes, coupled with the application of increasingly sophisticated processing algorithms, allowed for much more rapid improvement in operational capability at significantly lower cost. Concurrent changes in the acquisition process (a.k.a. "Acquisition Reform") changed the roles and interactions between government and industry in order to expedite delivery of the best capability to the fleet. The new and improved process changed how products were developed and delivered but still supported the traditional (i.e., Cold War) approaches to undersea warfare (USW).

The second, current, post-Cold War period of adjustment is still ongoing and represents an even more dramatic change--a search for a more significant transformation of warfighting capabilities. The criteria for transformation postulated by Vice Adm. Arthur K. Cebrowski, USN (Ret.), former president of the Naval War College, includes a determination of whether a new capability:

* Enables a new concept of operation;
* Remains robust in the face of a wide range of threats;
* Broadens the base of future capabilities; and
* Profoundly alters competition more than legacy systems would.

Addressing the challenge will give rise to a new generation of the distributed networked systems needed to provide essential USW mission capability, and will alter both the undersea battlespace and the conduct of undersea warfare. The ultimate change will be a result of the confluence of emergent technological enablers and the co-evolution of the new technological systems with operational concepts and tactical employment.

The Future of USW

In order to achieve and retain access in the littorals, distributed and netted sensors and unmanned vehicles will be needed to complement shipboard and airborne systems not only to gain a pervasive situational awareness of the undersea battlespace but also to rapidly locate, target, and neutralize anti-access threats. Changes in operational concepts will reflect fundamental shifts in the balance between: (a) manned and unmanned vehicles; (b) "few, large" vs. "many, small" sensors; and (c) stealth vs. nonstealth.

Because of improvements in stealth technologies, future undersea adversaries will inevitably be quieter--and, therefore, more difficult to detect. This fact, coupled with the complex and cluttered environment of the littorals, will significantly complicate the challenge. A paradigm change, shifting from the current "sensor-poor" environment to a "sensor-rich" environment, is one transformational concept enabled by micro-electro-mechanical systems (MEMSs) and advances in nanotechnology that provide the ability to produce very small low-cost sensors and communication devices that can easily and rapidly be distributed in extremely large numbers.

The Naval Undersea Warfare Center (NUWC), together with industry and academic partners, is exploring the development of such devices, their application to evolving fleet operational concepts, and the resolution of related command-and-control issues.

Significant gains in warfighting effectiveness will be achieved through network-centric operations--i.e., the integration, interaction, and adaptation of sensors, information systems, platforms, and weapons systems enabled by a distributed netted system and focused on the 21st-century warfighter.

The Complexity of Large Numbers

The Navy's efforts in this field previously focused mostly on and above the surface of the water, but must now be extended into the undersea domain. The "large number sensor" approach will require additional demands for information relay. Research is underway to address the data rate, intermittency, and latency issues associated with today's undersea communications environment.

An undersea communications architecture must be developed that will be a functional adjunct to the global grid. Efforts are underway to develop a mobile ad hoc network, a group of wireless nodes that cooperatively and spontaneously could be used to form a network independent of any fixed infrastructure or centralized administration. Such a network would have no base stations, but would communicate directly with nodes within wireless range and, indirectly, with all other destinations dynamically.

However, as networks grow larger, their management becomes more complex. Agent-based network-management architectures will attempt to maintain smaller known networks and to group them together to form the larger undersea network and provide connections to the battle group, theater, and unified commanders. Such an approach is essential in the very-large-number sensor approach.

Sensors and their networks are only one piece of the expanded battlespace, however. Successful network-centric operations also will require the establishment of many new capabilities. FORCEnet--the Navy's transformational initiative to seamlessly integrate Navy and Marine Corps elements with joint, allied, and coalition forces--is defining the architecture and building blocks of sensors, networks, decision aids, weapons, and supporting systems integrated into a comprehensive, highly adaptive, and human-centric maritime system.

The Navy Warfare Development Command's ESG (Expeditionary Sensor Grid) concept will give physical form to the initiative. ESG will permit the integration of large numbers of locally controlled, distributed sensor systems with processing and communications capabilities. Local commanders will be able to quickly collect and manage more accurate and more timely data to reduce the latency of information and produce better-informed combat decisions.

An Array of Difficult Issues

The current "vision" for ESG encompasses sensors that are: (a) persistent/long-endurance (e.g., tied in to fixed undersea arrays); (b) moderate-endurance (e.g., large "N" sensors); and (c) cyclic--e.g., unmanned vehicles. These sensors also will be covertly deployable from a variety of forward units, including submarines and unmanned vehicles.

The NUWC is also:

* addressing the difficult issues associated with information-handling, interpretation, and cognition through various venues; and
* exploring various visualization and animation techniques dealing with complex information comprehension, and has constructed a laboratory complex, linked to national and international partners, through which undersea battlespace experimentation can be pursued via real and virtual systems and platforms.

Because of their covertness, endurance, flexible payloads, and ability to perform tasks unachievable by other means, submarines will continue to be one of the most important elements of the Navy's forward-deployed assets. Maintaining the stealth advantage of the submarine is essential. High-data-rate antennas and advanced buoyant cable antennas will dramatically improve communications efforts, but the real key to assuring unrestricted communications will be the greater utilization of through-water technologies.

Undersea acoustic communications (ACOMMS) systems use phase-coherent receivers to achieve medium data rates at speed and depth between and among submarines, surface ships, unmanned undersea vehicles, gateway buoys, and large-number sensors. Laser communications will provide high-data-rate underwater communications and, potentially, subsurface-to-air communications.

Visions and Vehicles

The future Undersea Battlespace will see a much greater use of unmanned undersea, surface, and airborne vehicles for a variety of missions. This represents another transformational change for undersea warfare.

NUWC shares a common vision for a family of unmanned vehicles, from small vehicles that will help populate the sensor grid to combat vehicles with a broad spectrum of mission capabilities. All will have the ability to operate with a high degree of autonomy, travel great distances, analyze the battlespace, communicate to multiple networks, launch attacks, and return to the host ship or deployment station--remaining covert, or nearly so, during the entire operational cycle.

NUWC has made a substantial investment in the future of unmanned vehicles. A great deal of emerging technology is required to make that future a reality, but NUWC researchers are reaching new goals every day. The Manta Test Vehicle (MTV) is being used, for example, to demonstrate and examine capabilities that will be evolved for use in future unmanned underwater communication vehicles (UUCVs), such as:

* Underwater acoustic communications;
* Above-surface radio-frequency links;
* The deployment of vehicles (ranging in size from 53 inches/70 lbs. to heavyweight torpedo-size);
* Bidirectional operator interactivity; and
* The transmission of optical data.

The NUWC will continue to develop and test new payloads and demonstrate additional unmanned underwater vehicle capabilities and to encourage other organizations and activities to take advantage of the MTV for demonstrations and tests of their system packages. In addition, the NUWC, working with industry and other laboratory partners, is embarking on a three-year program to demonstrate the utility of unmanned surface vehicles for a variety of surface missions.

Smart, Stealthy, Speedy

This future undersea environment also will require a new generation of weapon systems to address the challenge of the littorals. Several initiatives are being pursued to build a "smarter" front end for the torpedo. Acoustic and fiber-optic communications will provide the connectivity needed to allow the fusion of torpedo sensor data with platform information to provide an improved tactical picture for combat control systems. Improved connectivity between and among sensors and platforms and weapons will allow sensing/localization and attack operations to be conducted from different platforms. Intelligent controllers will enable the weapon to adapt to dynamic situations, using neural nets and fuzzy logic as well as new broadband-array technology to dramatically improve the sonar capabilities of the torpedo.

A truly stealth weapon will dramatically enhance submarine effectiveness, since the target under attack will not hear it until it is too late to evade, deploy countermeasures, and/or counterattack. Covert homing and signal-processing techniques as well as advanced passive technology are under development. Under consideration for the stealth torpedo propulsion system is a quiet hybrid electric propulsion system to further enhance its effectiveness.

The ability to kill a target before it can react also can be achieved through very high speeds as opposed to stealth. Being investigated is the development of a very-high-speed, autonomous, highly maneuverable, homing torpedo capable of speeds significantly in excess of those achieved by the current Mk48 torpedo. Using "supercavitation" technology, a torpedo becomes an underwater missile. In this approach, the water near the tip of the projectile (or torpedo) vaporizes, producing a vapor pocket that results in a dramatic reduction in drag. The same technology, applied to a range of weapons from bullets to torpedoes, offers additional operational capabilities against a spectrum of targets.

The mission of the NUWC is to provide products and services that directly contribute to ensuring superiority in the undersea battlespace. This challenge requires innovative approaches and concepts that the NUWC is co-evolving, in collaboration with other naval activities, with new operational warfighting concepts and tactics. This transformation is being approached by applying a total-
system-engineering perspective to a distributed USW Battlespace. The challenges are great, but the criticality of providing assured access against underwater threats demands an aggressive evaluation of all alternatives. *