Precision SIGINT Targeting System

by Lieutenant Commander Michael V. Cooperwood (USN) and Major John F. Petrik (USAR)

How do you get accurate target locations? Members of targeting cells distinguish targets from target indicators, which yield insufficiently accurate geolocation. Some of the United States’ most expensive and powerful collection assets—notably signals intelligence (SIGINT) systems—seem to fire support personnel too remote to be of any direct utility.

That view is not correct. Target indicators are invaluable in intelligence preparation of the battlefield (IPB), in cueing other assets capable of more precise target location, and in templating enemy activity. Furthermore, the design of the national systems was to meet national purposes; for security reasons, they often are deliberately difficult to access at tactical echelons. Nonetheless, the issue remains for targeteers and intel- ligence personnel: why can we not derive targets from SIGINT?


The problem is not unique to the Army. The Office of Naval Research (ONR) has long recognized that SIGINT’s considerable targeting potential was largely unrealized, and in 1994 took the lead in a joint effort to change that fact. In 1995, the Precision SIGINT Targeting System (PSTS) became an Advanced Concept Technology Demonstration (ACTD). The goal of the ACTD was to integrate currently available, emerging precision signals collection and pro- cessing technology into an operational system that could undergo testing and transition to operational forces in the shortest feasible time. The last PSTS demonstration was in September of 1998. The days where SIGINT has no immediate use to targeteers are gone.

The PSTS charter was to develop and demonstrate a near-real-time, precision geolocation, sensor- to-shooter capability using existing national and tactical SIGINT assets. Specifically, the goal was to integrate existing tactical and national SIGINT assets to provide battlefield operators with target locations more accurately than current systems could achieve operating independently. Moreover, the intelligence assets must achieve and disseminate more rapidly than they generally have in the past.

The ACT demonstration faced three major challenges. They were to—

Integrating Tactical and National Assets

What are the existing assets? There are sensitive national collection assets. These are extremely valuable sources seldom used for tactical applications. The demonstration had to develop ways of cueing these assets, analyzing their electronic catch, developing it into targeting information, and transmitting the target data to the weaponeers. These tasks posed conceptual, organizational, technical, and cultural challenges; they involved communications protocols, procedures, concepts of operation, and ways to share information without compromising it.

The tactical assets were obvious. The ONR focused on the Army’s Guardrail, an elegant sensor suite mounted on a C-12 fixed wing aircraft (the military version of the familiar King Air). The Guardrail system is a corps-level asset that has been in place for more than ten years. It is well equipped as a SIGINT collection platform.

To link the tactical and the national assets, the ONR used existing national communications systems and the Tactical Related Applications (TRAP) broadcasting system. TRAP was attractive because it represented an existing way of disseminating signif- icant electronic intelligence (ELINT) worldwide.

Under the ACTD concept of operations, Guardrail would acquire a signal and tip the national assets to tune in on the emission. The national assets’ data would go to an existing processing center for analysis and transmit a precise target geolocation via TRAP back to the division. There it would reenter ordinary intelligence and fire support channels, eventually winding up as a fire mission for a cannon battery. It was simpler to conduct fusion and analysis at the strategic-level processing station than to move these functions into an S2 shop. There were, however, risks associated with this: it increased the complexity of the tactical communications problem and it did little to allay the battlefield operators’ habitual suspicion of intelligence analysis. The demonstrations would determine whether this approach was feasible.

One also might wonder whether we could achieve the desired accuracy quickly enough to be useful. We expect most tactical targets to have a relatively short dwell time. Every potential enemy expects to be located because of their signals emissions, and the prudent ones take steps to help minimize those risks. Typically, various forms of emission control and frequent displacements achieve security.

Emission control will only provide limited value: if they are not using their electronic assets for fear of losing them, it is almost as effective for us as if they had lost them. Eventually they will radiate, and when they do, we have a fair chance of detecting it. Frequent displacement is more difficult. It will take the enemy time to use their radars (for it is air defense (AD) and weapons-locating radars we are interested in finding and destroying) but they will make that time as short as possible—radiate and move. Whatever PSTS did would have to be quick.

What the Demonstration  Showed

The results were encouraging. The ONR ran a series of demonstrations culminating in the September 1998 effort. The Light and Special Division Interim Sensor (LSDIS) (an AD radar) and AN/TPQ-36 Firefinders (a weapons-locating radar used for counterbattery purposes) simulated the threat radar systems. These systems participated courtesy of the U.S. Forces Korea (USFK) 2d Infantry Division, which also provided the tactical command and control links and the actual shooters—in this case the 2d Battalion 17th Field Artillery. The Guardrail came from the 3d Military Intelligence Battalion.

The first tests showed an ability, using existing SIGINT and communications systems, to acquire the emitters with an accuracy within 1000 meters. This is useful from an intelligence point of view, but fire support personnel need more precision. This improved to the point where the PSTS was giving the batteries target locations accurate enough to engage with cannons.

The speed was also impressive. The PSTS team hoped to break 15 minutes, and they did. The average time from a Guardrail tip to the TRAP dissemination of the target was under 12 minutes, and we anticipate being able to reduce it to six or seven minutes.

Observations and Lessons Learned

Operationally, the ACTD found that preplanned ELINT tasking is critical for routine operations. Assets are not always readily avail- able, and many customers compete for SIGINT products. They are not difficult to obtain, but one must plan for them in tasking. The PSTS demonstration taught the lesson that intelligence personnel must work closely with their counterparts in fire support

The demonstration also found that operator proficiency in the Guardrail-associated systems was essential to timely targeting. The good news is that the operators can (and did) exhibit a high degree of proficiency, and that most training requirements are satisfied by Advanced QUICKLOOK training and missions.

Finally, on the operational side, we learned that collection management requires extensive cooperation and coordination. Both coop- eration and coordination are always most difficult to achieve with new systems and across Service lines. However, the personnel who worked on the PSTS got it right even under those demanding conditions.

Technically, we saw the importance of PSTS collection times, when compared to the hostile emitter’s on-off cycle. We also saw that the relative geometry of the cooperating collectors over time was critical to achieving the accuracy desired. Finally, we saw that Guardrail’s sensitivity suited it well to assume primary responsibility for tip-generation during PSTS Demonstration 5.

The Future of PSTS

Part of the future is already here. One of the nice things about Advanced Concept Technology Demonstrations is that they traditionally leave behind a real operational capability. The prototypes did not all return to the labs, but some remained in place with USFK.

The future holds other challenges. Some of the challenges are straightforward. The ONR demonstrated the system with Guardrail. Now that the ACTD is complete and the system has been handed over to the Airborne Overhead Interoperability Office, the AOIO will seek to extend the capability to other airborne platforms: the EP-3, Rivet Joint, and the U-2. Other issues the AOIO is researching include assessing how to best use the scarce Tactical Receive Equipment (TRE) operators to receive TRAP broadcasts.

We also wish to extend the SIGINT capability from noncom- muncations emitters more broadly. When the AOIO succeeds in demonstrating the ability to target communications emitters, it will introduce an extremely important new capability.

The ONR has a winner in the PSTS; one we would not have without outstanding cooperation from the Army’s intelligence community. Others believe it is a winner as well. Brigadier General Nicholas Grant, Director of Intelligence, USFK J2, called PSTS “a significant enhancement to the theater’s collection capability.”

Major General Robert W. Noonan, Jr., Commander, U.S. Army Intelligence and Security Command, said,

The Precision SIGINT Targeting ACTD shows great promise for warfighters. It has laid the foundation in USFK that can now be migrated to other CINC AORs to build robust tactical-national ELINT targeting capabilities. More importantly, it lays the foundation for a robust tactical-national COMINT tar- geting capability. When the community achieves COMINT targeting, the full potential of PSTS will be realized.

The best news is that all the Services now have a new and powerful targeting system available today in the Korean peninsula. Anyone interested in the system is invited to contact the ONR through its website, http: // www.onr. To go directly to the PSTS web page, follow

Lieutenant Commander Cooperwood enlisted in the Navy after high school and entered the Nuclear Power Program. Following his completion of nuclear power training, he boarded the USS California in  where he completed a global circumnavigation. He  received a Naval Reserve Officers Training Corps scholarship to the University of South Carolina, where he received a Bachelors of Science degree in Electrical Engineering. Subsequently, he served as Electrical Officer and Anti-Submarine Warfare Officer aboard the USS Jouett, and then as Combat Information Center Officer aboard the USS Belleau Wood. He transferred to Engineering Duty and served as Ship Superintendent at SupShip in San Diego. LCDR Cooperwood earned a Masters of Science degree in Electrical Engineering from the Naval Postgraduate School. Since then he has served as a Project Officer for the Link-6/TADIL (Tactical Digital Information Link) J Program Office and was instrumental in developing the extended range enhancement to Link-16 known as Satellite TADIL J. Since 1997, LCDR Cooperwood has been at the ONR where he currently serves as the PSTS ACTD Program Manager.

Major Petrik works for Noesis, Inc., a consulting firm based in Virginia, and supports the Office of Naval Research. A major in the United States Army Reserve, he served on active duty for twelve years in a variety of Field Artillery assignments, including an extended tour with V Corps Artillery in Germany and three years as Combat Trainer with the Fire Support Training Team at the National Training Center, Fort Irwin, California. He holds a Bachelors degree from Middlebury College and a Masters degree from the University of Chicago, and has taught at both the United States Military Academy and Rockhurst College.