Blue Force Tracking: a subset of combat identification

Military Review, Sept-Oct, 2004 by Kurt Dittmer

AS THE ARMY transforms to lighter, leaner, more lethal future combat systems, Army leaders can draw significant parallels from air combat when considering new combat identification (CID) capabilities. The U.S. Air Force (USAF) has had Blue Force Tracking (BFT) and Blue Force Situational Awareness (BFSA) for decades. Army Transformation planners should consider moving CID out of the oversight of the Joint Staff Command and Control Functional Control Board to the Force Application Functional Control Board.

Identification, Friend or Foe

The British developed an electronic identification device for aircraft during World War II to provide a "friendly" reply to a ground radar's interrogation. (1) The device, appropriately named identification, friend or foe (IFF), was a combination transmitter and receiver (called a transponder) that used a unique signal to identify the aircraft. Because only friendly or enemy combatant aircraft were flying over England, any aircraft not "squawking" was probably a German combatant (or a friendly combatant with malfunctioning equipment). With a lethal envelope of weapons in the visual arena, verification during engagement could reduce the chance that a friendly aircraft would be shot down.

In today's air combat environment, airspace contains more commercial and private aircraft, all equipped with IFF transponders, which routinely transit airspace or approach combat zones. Because the range of air-to-air and surface-to-air weapons systems has expanded, lethal engagement envelopes have also expanded well beyond visual ranges, and the need for identifying friend from foe has required more capabilities.

Transponder modes 1, 2, and 3 on all U.S. military aircraft provide aircraft, flight, or other group or class information. Mode 4, an encrypted code, can only be interrogated by systems with current cryptography codes. (2) information from these IFF interrogators and transponders feeds the ground and air surveillance radar picture for Joint BFSA (JBFSA) of airspace. Airborne fighters with an advanced interrogation capability can display a piece of the air picture, although their field of regard limits them. A fighter's radar typically only looks in front of the aircraft, and its displays merely overlay the transponder displays with raw radar returns. If an IFF transponder system is inoperative, the interrogation will come up negative, indicating "lack of friendly" (LOF), and the radar return--the IFF--with the wrong code goes into a category called "unknown."

With access to an enemy's IFF and codes, the interrogation of a foe and a subsequent positive response will indicate "presence of enemy" (POE). This does not complete the "kill chain" for engagement, however. The POE identification must be further assessed to determine whether the aircraft present is a combatant with hostile intent (that is, whether a MiG-29 identified is trying to destroy or trying to defect).

Combat Identification

JBFSA interrogation and friendly force response has nothing to do with identifying enemy personnel or equipment; it is only cooperative identification. JBFSA feeds the information into CID by providing information on friendly troops, but it is really only a subset of the overall capabilities required to achieve true CID.

The 2001 CID "Capstone Requirements Document" defines CID as "the process of attaining an accurate characterization of detected objects in the joint battlespace to the extent that high confidence, timely application of military options, and weapons resources can occur." (3) This definition points toward the fundamental objective of destroying the enemy, the end result of closing the links of a kill chain. The USAF talks about a kill chain as a set of capabilities to find, fix, track, target, engage, and assess hostile enemy aircraft.

In the kill-chain sequence, find encompasses locating friendlies, enemies, and neutrals. Fix is the process of characterizing potential targets with sufficient fidelity for proper weaponeering and engagement. (4) Fixing includes the precise location as well as CID of aircraft. Combat identification at this juncture starts with cooperative identification capabilities to determine cooperating friends. But CID requires entirely different capabilities to perform noncooperative identification. Noncooperative identification capabilities must distinguish neutrals from enemies to link up the rest of the kill chain.

CID is not final as a pilot transitions from fix to track to target. With sensors and platforms brought into the process, the goal continues to be to engage enemy forces. At any time during this process the kill chain can be broken to prevent fratricide.

The term "fratricide" has taken on disproportionate importance because it describes sensitive incidents. But, if the only goal is to prevent fratricide, one can do so by never firing a shot. From the standpoint of effectively destroying the enemy, fratricide is but one metric by which to measure poor CID.

Procuring capabilities to prevent fratricide is necessary, but elaborate CID capabilities potentially slow down the ability to engage and destroy the enemy. BFT and JBFSA do not complete the kill chain; they break the kill chain. With refresh rates potentially in the range of several minutes, waiting for a BFT interrogation could actually increase force vulnerability.