Dual-Band Radar (DBR)

The DBR concept combines the detection capability of the SPY-3 system on the horizon and the VSR in the volume to efficiently respond to surveillance, track, threat assessment, and engagement support commands from the ship's combat system. Coordinated resource management, scheduling and tracking provide potent functionality to provide quick reaction cued acquisition to threat targets, dual band counter to electronic attack, backup L-band horizon search coverage during X-band missile illumination support, and balancing of precision tracking radar resources. Control of each radar at the waveform level promotes a more optimized usage of both frequencies to maximize utilization of the radar timeline and increase search and track revisit rates. Correlation of detection measurements in a centralized track database provides for improved precision threat track, minimized fades and reduced susceptibility to electronic attack. The DBR concept also provides an excellent ATC capability for CV(X) operations; whereby, the VSR handles air traffic marshalling and the MFR supports precision landing.

The Dual Band Radar (DBR) combines the functionality of the X-Band AN/SPY-3 Multi-Function Radar with that of an S-Band Volume Search Radar (VSR). X-band advantages include superior low-altitude propagation effects, narrow beam width for best tracking accuracy, widest frequency bandwidth for effective target discrimination and submarine periscope detection, and the necessary target illumination frequency for SM-2 and Evolved Seasparrow Missiles (ESSM). S-band advantages include a high-power aperture for effective search functionality, acceptable propagation loss regardless of weather, and sufficiently small beam width to resolve and track targets accurately.

Both bands are capable of providing effective uplink/ downlink capabilities to interface seamlessly with the ship's surface-to-air missile systems. Operating simultaneously over two electromagnetic frequency ranges (X-band and S-band), the DBR marks the first time this functionality has been achieved using two frequencies coordinated by a single resource manager. As a result, the system delivers capabilities and flexibility not possible with earlier generations of land and maritime radar systems.

Many of the search and track functions can be allocated to either or both frequencies. Horizon search (to detect anti-ship cruise missiles) and precision track (to provide high update rate, fire control quality data) are examples. Since environmental phenomena affect different frequencies in different ways, the ability to bring both frequencies to bear increases performance during multipath and anomalous propagation. In addition, in situations where one band becomes taxed (such as when supporting multiple missiles in flight), the other band can effectively share the workload.

As a class, phased array radar systems have done much to improve reliability, essentially by their absence of moving parts in the antenna. The DBR takes this to the next level: The active electronically steered arrays have been engineered to offer graceful degradation, thereby minimizing the possibility of systemwide or single-point failures. Built-in redundancy ensures system operability if radar component failures occur. The DBR is designed to operate 24/7 over a very long mission time at an operational availability better than 95%.

The DBR contains a robust fault detection/fault isolation system, which notifies the ship system of any required maintenance. Replacement of components for the DBR arrays, subsystems, computers and other ancillary equipment typically involves swapping out circuit cards, solid state transmit/receive integrated multichannel modules (TRIMMS), or other modular components, all of which keep potential down time to a minimum. Access to all antenna components is from the rear, which will permit servicing from within the ship. The DBR is being designed to require fewer than 100 hours of corrective and preventive maintenance per mission-year and has a mean time to repair (MTTR) of less than 30 minutes.

The DBR requires no dedicated operator and has no manned display consoles. The system automatically senses the complex man-made and natural environment and adjusts its processing accordingly. Specific tactical radar behavior is governed by doctrine, entered by a tactical action officer or sensor supervisor within the ship's Total Ship Computing Environment (TSCE) or host command and control system. Being fully automated, the DBR takes the reaction time associated with manual operator action out of the loop and eliminates the potential for human error associated with manual radar settings. The only human interaction involves maintenance and repair activities, performed by technicians using a maintenance local area network (LAN) that allows them to take control of the radar and to run offline tests.

The DBR is the first radar for which complex signal and data processing is done entirely in a Commercial-off-the-Shelf (COTS) computer. Computing products from IBM, Hewlett-Packard and Sun Microsystems all offer competitive, capable solutions. All DBR software has been designed using objectoriented techniques and is written in the widely used C++ and Java languages. DBR software is fully interoperable with the TSCE, an Open Architecture (OA) solution that integrates all of the ship's computer functions into a single enterprise network. The TSCE also serves as a basis for the Navy standard combat system, designed for fleet-wide use.