A Boost for Sea-based Radars
Written by Erin Flynn Jay
SPY-1 Radars on AEGIS ships currently provide tracks
in the long range surveillance and tracking mission to
the BMDs. The SBX is undergoing modifications and
upgrades to enhance capability, and improve
safety and performance.
“Cooperatively, government technical experts, research labs such as MIT and JHU, along with industry and service engineering experts took the margin in the system and developed a capability to detect and track objects in space, which is the essential challenge posed by this new and demanding mission needed by the warfighter,” Navy Captain Randy Hendrickson told MSMF.
By employing the radar resources, or transmission dwells, that SPY produces and packages in high energy and programmable energy waveforms, the AEGIS weapons system BMD computer program has been adapted to establish a so-called “search fence” in the vicinity of an expected ballistic missile launch, which captures a threat missile as it rises above the radar horizon. Once a firm track on the threat missile is obtained, the ruleset within the AEGIS weapons system is modified to produce a fire control track on a higher, faster and more distant object than originally designed into the combat system.
“Ever since the early versions, we have improved the program on a spiral basis by concentrating on using the SPY radar’s resources more effectively to obtain better performance. In the process, radar resources are made available for other missions such as air surveillance and ship self-defense,” said Hendrickson. “On the receive side, improvements continue to be made in the radar’s signal processing, which aids in discrimination of the intended lethal object in the target complex, and also improves the radar’s ability to perform in high-clutter environments as well as employ current and future variants of the SM-3 missile.”
The Navy realizes the sensitivity that the current version of SPY-1 possesses is its limit and the threats it faces continue to develop ever-increasing sophistication. “As the threat becomes more stealthy, or the number of simultaneous threats increases, we will need a more powerful and more sensitive radar. This radar would have the sensitivity to see smaller and smaller objects at range or to discern and discriminate a number of closely-spaced threats traveling together,” said Hendrickson. “This requires a radar that uses advanced technology, such as an active array, or a larger power aperture, or a combination of the two.”
NAVY DEVELOPING ADVANCED MISSILE
Navy is in the early stages of developing such a radar, which it named the AMDR. The service is considering installing an objective system on a CG(X)-type hull, and possibly other classes of ships, because the design approach builds a radar that is scalable with open architecture.
Since BMD is so demanding, MDA has adopted the so-called “any sensor, any shooter” slogan to represent its view of the global requirements for this mission in the future. “To facilitate a setup that enables, for instance, firing a silo-based groundbased interceptor in Alaska using radar data from an ABMD ship in the far western Pacific, MDA is developing the ballistic missile defense system [BMDS] and associated command and control architecture,” said Hendrickson.“This system, without getting too technical, will comprise the network that forms the ‘connective tissue’ by which disparate sensors and shooters can exchange the combat information necessary to make ‘any sensor, any shooter’ a reality.”
Today, SPY-1 radars on AEGIS ships provide tracks in the long range surveillance and tracking (LRS&T) mission to the BMDS. “In this role, we capitalize on the inherent mobility and flexibility of ships to operate forward and reposition as the threat requires. In the case of SBX, it is the world’s most powerful X-band radar and will enable a degree of discrimination capable of discerning advanced threats,” said Hendrickson. “The ‘plug and play’ aspect of the BMDS architecture will make sensor data available to detect, classify and engage the global ballistic missile threat ... rather like the way the Internet functions as an information repository on a global basis.”
The Navy became the lead service for Sea-based X-band (SBX) late last year as directed by the deputy secretary of defense. The designation of lead service came after the Navy and MDA negotiated a memorandum of understanding for transfer and transition activities. The CNO, Admiral Gary Roughead, and former director, Missile Defense Agency, Lieutenant General Trey Obering, agreed to a two-year transition period to build the longterm foundation for SBX operation. The Navy will serve as the lead service for operations and sustainment of the SBX propulsion equipment and the vessel. MDA will continue to develop and install spiral improvements to the radar, much as they are developing capability spirals for other elements of the BMDS.
Likely improvements will feature the same sort of leap-ahead technology that will characterize Navy’s AMDR. MDA will retain development control of this radar indefinitely. MDA’s current plans call for only one SBX platform to be delivered.
BMD is often referred to as rocket science and held up as an example of complexity. “Radar development is certainly a key aspect of BMD, but it is not the only one as I have mentioned, and is equally complex. Clearly the AN/SPY-1 radar series is an example of how a then-revolutionary concept, phased-array radar technology, can be fine-tuned, product-improved, and adapted to new and difficult applications over a period of time,” said Hendrickson. USS Ticonderoga (CG-47) was commissioned in 1983, and AEGIS ships with the SPY-1 radar will continue in service well beyond the middle of this century.
“The stakes are high, and we are collectively aiming for a development across several components that will prove to be as successful as SPY-1. Navy, the MDA and the defense industry are working toward the next technological advance phased arrays and the combat systems, command and control architecture, as well as continued improvements to existing systems to meet and get ahead of the threat posed to our nation, forward-deployed forces, allies and friends,” Hendrickson concluded.
SBX INVOLVED WITH GROUND TEST
Additional components, new technologies or updated capabilities are brought into the BMD system through integration and testing. SBX is currently involved with a key ground test of the BMD system that will ensure SBX can operate seamlessly with other assets of the BMD system, said Greg Hyslop, vice president and general manager, Boeing Missile Defense Systems.
Performance and capability of the SBX has been proven in previous tests of the Ground-based Midcourse Defense system. SBX demonstrated maturing performance and integration with the BMD System in two recent large-scale BMDS tests: FTG-05, a live intercept test in December 2008 and FTX-03, a simulated flight test in July 2008, said Hyslop. In both tests, SBX acquired the target as well as provided accurate target track and discrimination data resulting in successful intercepts of a target in both tests.
The SBX is currently undergoing modifications and upgrades to enhance capability, and improve safety, availability and performance. “Some of the major vessel modifications include the addition of a crane on the port side and upgrades to the starboard side crane to enhance loading at sea,” said Hyslop. “In addition, the support infrastructure for the in-water mooring system is being completed. Software improvements are also being developed to improve SBX capability to track and discriminate ballistic missiles launched against the United States, our deployed forces, and our friends and allies.”
SBX is an integral part of the Ground-based Midcourse Defense system, which is the only defense the United States has against long-range ballistic missiles. It was developed by Boeing, exclusively for the GMD program to track, discriminate and assess ballistic missile threats.
In July 2008, SBX achieved a declaration of early capability delivery from the Missile Defense Agency. This decision certifies that the SBX, when linked to the GMD fire control system, has the ability to provide object tracks and discriminated targets for GMD’s ground-based interceptors to address during a real-world threat, said Hyslop.
Prior to this declaration, the SBX was available for operational use in a data collection mode, at MDA’s discretion. The declaration now confirms the agency and warfighter community’s confidence in the connection of SBX to the GMD fire control system when called to defined operations.
SPY-1 SENSOR FOR AEGIS
The SPY-1 radar is the primary sensor for the Aegis BMD weapons system. According to Lisa Callahan, Lockheed Martin’s vice president for Maritime Ballistic Missile Defense, it offers:
Long-range surveillance and track: The power of the phased-array, fixed face S-band radar is designed to provide target discrimination at long ranges, and track multiple targets simultaneously. In this capacity, the SPY-1 becomes a significant sensor in the nation’s BMD System, in which the SPY-1 data is transmitted to other elements of the BMDS (such as the Ground-based Missile Defense system).
Engagement: SPY-1 is critical in all phases of an intercept, including the initial detection, tracking and targeting of the ballistic missile. In addition, SPY-1 tracks the SM-3, provides in-flight guidance up to the terminal phase, and maintains two-way communication with the SM-3.
Engagement based on Tactical Action Data Link (TADL): Aegis BMD is designed to initiate an engagement using data from an off-board sensor, such as another Aegis-equipped ship or a land-based radar. In this scenario, the Aegis BMD weapons system will launch the SM-3, and the SPY-1 will feed the TADL updates to the SM-3 until the SPY-1 detects the ballistic missile. When SPY-1 gains detection, it uses that data to continue guiding the SM-3 to the terminal phase.
PLANNED UPGRADES FOR SPY-1 RADAR
Aegis BMD 4.0.1 will include the production and installation of the Aegis BMD signal processor (BSP). “The BSP will improve radar resolution, thus allowing Aegis BMD to engage more complex targets,” Callahan told MSMF. Aegis BMD 5.0 will transition all Aegis BMD capability to COTS and open architecture, and fully merge BMD with the Aegis Weapons System’s advanced capability build 12 (ACB12).
ACB12 is the designation for development evolutions of Aegis open architecture, and will be fielded on Arleigh Burkeclass Aegis-equipped destroyers in 2012 as part of the Navy’s Aegis modernization program. As the modernization progresses, all Arleigh Burke-class destroyers that complete the program will have BMD capability, Callahan said. When the final Burke destroyer commissions, there will be 62 ships in the class. Regarding the radar, Aegis BMD 5.0/ACB12 will include the multimission signal processor, which combines the BMD capability within the BSP with the Aegis multimission capability into a single processor.
Callahan said other enhancements in Aegis BMD 5.0/5.1/5.2 are:
- Enhanced integration with other BMDS systems, such as SPY-1 data being used by other BMDS systems for detecting, tracking and targeting. Likewise, Aegis BMD will have enhanced capability to use data from other systems.
- Engage on remote capability, where Aegis BMD ships can use off-board data to launch and guide the SM-3 for the entire engagement. This will be supported by the addition of the SM-3 Block IIA missile, which will have a much greater range than the current SM-3.
- The current terminal phase capability in Aegis BMD 3.6.1 will be upgraded, which will require SPY-1 and signal processor upgrades to support the endo-atmosphere algorithms for target discrimination, and guidance enhancements to support SPY-1 communication with the new missile (yet to be determined by the Navy/ MDA).
With the evolutions in signal processing capability, Aegis BMD will be able to better discriminate targets—especially in terms of smaller separating targets and countermeasures.
Interoperability between SPY-1 on Aegis BMD ships and other elements of the BMDS will extend the battlespace by increasing the surveillance area and using the best available option to conduct the engagement.
Lockheed Martin’s expertise in S-band radar technology is established in the SPY-1 family, and has set the standard on radar operation and capability in a sea/maritime environment. “Building on this success, we have also developed a next generation S-band solid state radar technology. As the Navy determines its plan for future sea-based missile defense assets, we believe our solid state radar technology is well positioned to meet their needs with minimal development time,” Callahan said. “Through internal investment, we have developed our scalable solid state S-band radar (S4R) to the EDM level.” ♦