Synthesizing Capabilities Thwarts Growing Ballistic Missile Threat

January 2000
By Lt. Cmdr. Tina Bigelow, USN

U.S. Navy answers call for stronger defenses by expanding reach to the electronic stars.

Ongoing operations that examine the convergence of current U.S. military information-gathering capabilities may lead to enhanced systems that will more effectively combat theater ballistic missile threats. Research underway by the U.S. military focuses on more effectively exploiting the information provided by overhead nonimaging infrared satellites to support naval missions. Looking into the next century, military officials believe that more capable, future satellite sensor systems will enable the next generation of naval warfighting forces to gain the efficiency and effectiveness required to expand their umbrella of operations.

Iraq's use of Scud missiles against allies and coalition forces during the Gulf War illustrated the need for timely detection and dissemination of data on short-range theater ballistic missiles. In response, the U.S. Army and U.S. Navy jointly developed the joint tactical groundstation. Building on existing U.S. Defense Department support program (DSP) satellite capabilities, the technology was developed and certified as an initial operational capability several years ago. Since that time, the station and its prototypes have been functioning as the in-theater element of the theater event system architecture, providing direct support to warfighting commanders in chief at two overseas forward-deployed sites.

The exploitation of overhead nonimaging infrared data accomplished using the joint tactical groundstation (JTAGS) system in support of the operating force may be just the beginning. DSP satellites will be replaced early in the next century with the more capable space-based infrared systems (SBIRS).

JTAGS uses the space-based overhead nonimaging infrared data received from the DSP satellite downlink to support tactical users. The exploitation of this data for tactical purposes does not adversely affect the constellation's original and continuing strategic mission to provide early detection and warning on long-range missiles.

The station receives and processes raw wideband infrared data from the geostationary DSP satellites in theater. In contrast, the U.S. Air Force's attack and launch early reporting to theater (ALERT) system, the continental United States-based element of the theater event system, uses a bent-pipe architecture to receive DSP data in the continental United States for processing. JTAGS operators can detect theater ballistic missiles (TBMs) shortly after launch and follow their progress through booster burnout. Tracking the event is the detect phase. The operator manipulates raw data, then progresses into the assessment phase. Here, the TBM information is evaluated and analyzed against specific missile profiles, which in turn enables the generation of estimated launch point and time, predicted impact point and time, and three-dimensional trajectory parameters. This information is then broadcast through existing in-theater communications networks, completing the dissemination phase of the JTAGS process.

The disseminated data can be used for alerting and cueing information on TBM threats as well as other significant infrared tactical events of interest. These capabilities, combined with the ability to simultaneously track multiple events, are making the technology a vital part of the theater commander's situational awareness toolkit.

The Navy's tactical exploitation of national capabilities (TENCAP) research and development program focuses on improving JTAGS capabilities through the Radiant Gold project. This effort seeks to better the fleet's ability to respond to TBM threats in three specific areas. The first, considered passive defense, could warn U.S. Marine Corps and other deployed forces ashore of incoming missiles. The second area, active defense, involves engaging incoming missiles. The third area, attack operations, would include launching counterstrikes against enemy missile forces. Radiant Gold also is researching various options for improving JTAGS communications and reporting methods to support situational awareness and near-real-time cueing of Aegis cruisers engaged in TBM operations.

The Navy's TENCAP has already transitioned the project's remote JTAGS (RJTAGS) prototype suites to an operational status, providing situational awareness to joint task force commanders in theater ballistic missile operating environments. The remote systems are currently installed as stand-alone systems at Navy Central Command headquarters, Bahrain, and on each numbered fleet flagship.

Another thrust of the Radiant Gold project is improving the timeliness of TBM cueing information for the Aegis weapon system (AWS). Topside space restrictions on Aegis ships make it difficult to envision the installation of the large antennas needed to support an autonomous JTAGS capability. Deployed station units use three 8-foot dishes to acquire their DSP downlinks. Project participants are developing a capability to provide processed data from a JTAGS ashore, using new data formats and communications protocols.

SBIRS is the next-generation replacement for the existing defense special program system. Developing as a system of systems, its aim is to consolidate the benefits of a more capable satellite sensor system with new and existing ground processing systems such as ALERT and JTAGS. Utilizing three basic satellite configurations together with a consolidated ground segment, SBIRS will provide the warfighter with more effective integration of space-based, overhead nonimaging infrared data.

The three SBIRS space-based segments will consist of four satellites in geostationary earth orbit, two satellites in highly elliptical orbit, and an undetermined number of satellites in low earth orbit. The basic components of the ground segment will be a central ground processing station called the mission control station (MCS); and deployable units, or multimission mobile processors (M3P). ALERT will transition into the MCS, and JTAGS will evolve into the M3P.

The SBIRS geostationary earth orbit and highly elliptical orbit constellation elements are in development under the system's high program. The low earth orbit satellite segment is being developed under the SBIRS low program.

SBIRS high will be deployed first as a direct replacement for the current DSP system. These satellites will provide improved global and theater overhead nonimaging infrared data concerning the launch, boost flight phase, and impact areas of strategic and theater missiles. SBIRS low is being designed to supply tracking information during the midcourse and re-entry flight regimes.

As an essential element of the Navy's "ForwardÉFrom the Sea" doctrine, the Aegis capabilities are the basis for a sea-based ballistic missile defense system. Having this mobile firepower in the theater ballistic missile defense arsenal will support theater commanders.

The Navy theaterwide system, an upper-tier defense program with the Aegis weapon system as its cornerstone, and the Air Force's SBIRS low program are both in the early development phases. This creates an opportunity in which a true family-of-systems approach is possible. The Aegis weapon system is a proven asset. It is based on a solid weapon system foundation featuring the Spy radar and a standard missile. The Navy theaterwide system will build upon this successful foundation with a new interceptor designated as the SM-3. The SM-3 will be a long-range missile, using the lightweight exo-atmospheric projectile. The longer range of the SM-3 facilitates the possibility of using off-board sensor data like SBIRS low to expand Navy battlespace.

SBIRS low could offer space-based overhead nonimaging infrared data that could provide both two- and three-dimensional, real-time data for utilization within Aegis to enhance the employment of the SM-3 interceptor.

Several scenarios with SBIRS information supporting Aegis operations can be envisioned. Both SBIRS high and SBIRS low satellite data may be used to cue the Aegis radar. In this scenario, cue quality target state vectors would be processed by the Aegis weapon system to acquire the target missile using high-energy radar waveforms, which are not used under normal search operations. As a result of earlier radar tracking, the SM-3 interceptor could be launched sooner.

In another scenario, early commit operations could use the output of the SBIRS low configuration. The Aegis fire control solution would be generated by nonorganic overhead nonimaging infrared track and measurement data from SBIRS. The Aegis missile would be launched prior to the firm radar Aegis weapon system track such that the endgame would occur within the Spy radar envelope. Target update data would be routed to the missile through the onboard Aegis weapon system.

Remote engagement operations would escalate SBIRS low utilization one step further. A fire control solution would be generated by the Aegis weapon system via nonorganic track and measurement data from SBIRS. The Aegis missile would be launched, and intercept would occur based solely upon this information. Although updated data would be routed to the missile through the Aegis weapon system, the actual detection and engagement of the enemy's missile could occur beyond the capabilities of the organic assets.

Full utilization of these engagement scenarios requires more research and development of joint concepts of operations, but many potential benefits could be realized.

Improved situational awareness, expansion of the battlespace, increased depth of fire and the ability to shoot smarter are some of the possibilities the combination of SBIRS and the Navy theaterwide Aegis capabilities could offer. Realizing these new warfighting capabilities will require close coordination among the services and an openness to new concepts. It is envisioned that both early commit and remote engagement concepts of operations will require direct downlinks of SBIRS low fire control quality tracking and discrimination data. Additionally, SBIRS hit-and-kill assessment data will be required if the SM-3 endgame occurs beyond the Spy radar envelope.

Overhead nonimaging infrared utilization has seen a maturation cycle from the 1970s Defense Department support program to today's JTAGS/ ALERT applications. SBIRS and the Navy theaterwide program may offer a synergistic effect, allowing the naval warfighter to realize benefits beyond those that would be achieved through a traditional combination of each individual element.

Lt. Cmdr. Tina Bigelow, USN, is currently assigned to the AFCEA Fellowship Program.

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