Sea Shadow Tests Combat Systems

The U. S. Navy’s Sea Shadow, de­veloped as a test platform for signa­ture control, automation, sea keeping, and ship control, has recently been testing ad­vanced combat systems prototypes.

The new systems were designed to be driven by active radar, passive sen­sors, and Tactical Data Link-11 and -16. Sea Shadow test profiles dictated that the prototypes operate in a receive-only mode for Link-11 track information, relying on off-board sensors for all input. Reference data, including maps and commercial air­ways, were loaded into the prototypes to cover testing along the Southern Cal­ifornia coast.

Two prototypes were tested:

• The Automated Combat Identification System (ACIDS) is a decision aid that identifies automatically air and surface tracks based on sensor and intelligence information as defined by the tactical operators.
• The Tactical Action Adviser (TAA) is a decision aid that supports a shipboard tactical action officer or warfare commander in deter­mining threats to their own ship based on her signatures, threat sensors, and threat weapons.

Such systems are of value to various platforms, but are par­ticularly important when mission requirements preclude the use of active sensors. Off-board track informa­tion contains detailed positional information and identification indicators that must be interpreted by each platform to determine the threat and appropriate response for that platform.

The Advanced Research Projects Agency (ARPA) funded the testing and demonstration of the proto­types as part of the High Performance Distributed Ex­periment (HiPer-D) program. The software for both pro­totypes used technology funded by the agency for civilian and defense appli­cations.

“HiPer-D demonstrated that advanced software tech­nology such as modern op­erating systems, distributed computing, and replication for fault tolerance can meet the needs of combat system applications; and that they provide a natural migration path to new computing sys­tems as they evolve. ARPA. Aegis, and NavSea [Naval Sea Systems Command] are leading the introduction of these tech­nologies so that our fighting ships of the future won’t be locked into 20-year old custom military computing technology,” Lieutenant Colonel Brian Boesch, U.S. Air Force, ARPA program manager, said.

Combat systems historically have been developed using custom military com­puters and operating systems, denying de­signers the opportunity to take advantage of significant improvements in commer­cial computer processing power and com­mercial operating system capabilities.

Commercial computers and operating systems, however, are not designed for some of the more demanding combat-sys­tem applications and the HiPer-D pro­gram has defined the requirements most difficult for commercial systems to meet and demonstrated that the requirements can be met.

The ACIDS prototype’s purpose is to address the three outstanding require­ments in today’s tactical systems;

• Fusion of numerous and diverse sources of sensor and identification in­formation previously unused in the track identification process
• Automation of manual identification tasks
• Production of timely, high-confidence identification responses

The system uses a knowledge-based network of rules to represent identifica­tion doctrine using a software design that simplifies system expansion and min­imizes response time. By introducing pre­vious track-identification and track-char­acterization conclusions into the identification process, ACIDS can pro­duce a high-quality track identification.

The TAA prototype’s purpose is to provide an integrated situation assessment and planning decision aid for a multi-­warfare decision maker. It allows tacti­cal decision makers to view real-time track information and intelligence infor­mation in a single support system that evaluates threat detection and weapons capabilities against the ship’s signatures, detection, and weapon capabilities.

Testing on the Sea Shadow showed that the ACIDS and TAA prototypes per­formed their combat system’s functions as designed, to include receiving real-time track updates via Link-11. The prototypes ran on a distributed network of six com­puters to demonstrate distributed com­puting; running a particular function in multiple processors meant that a primary function fault could be covered by a backup with no loss of data.

The Sea Shadow, operated by Lockheed Missiles and Space Company, proved an excellent test platform because of its large payload space, power- generation and air-conditioning capabil­ity, and its low pitch and roll even in high sea states.

Mr. Mayer is the Shipboard Command, Control, Communications and Intelligence Technical Direc­tor, Advanced Technology Laboratories, Lockheed-Martin, Camden, New Jersey.