JCAS data link: a prioritized approach to terminal attack control

This article focuses specifically on defining two data link capabilities key to enhancing the speed and lethality of joint close air support (JCAS) terminal control. This "bang for the buck" approach is intended to prioritize data link implementations that are attainable in the near-term and provide the most enhanced combat capability to the warfighter.

Although data links have the potential to enhance many aspects of JCAS from integration and coordination through battle damage assessment, the discussion in this article is limited to data link applications to close capability gaps in the execution of Type 1 terminal attack control. Complete Joint Combat Identification Evaluation Team (JCIET) and JCAS Joint Test and Evaluation (JT & E) reports are available on the Joint Fires Integration and Interoperability Team (JFIIT), Eglin Air Force Base, Florida, website https://jfiit.eglin.af.mil.

Current threats and precision-guided munition (PGM) technology have dramatically altered JCAS. Extended launch ranges, higher altitude and all-weather/day-night employment push command and control ([C.sup.2]) decisions and airborne target acquisition well beyond the visual arena. These changes make the already challenging terminal attack control process more difficult.

The commonly held perception that aircrews can positively identify friend from foe before weapons release has been proven false in JFIIT assessments. Additionally, even the best trained joint terminal attack controller (JTAC) can't accurately predict a weapon's impact point in this environment. Failure to correct these basic deficiencies in visually based terminal attack control equates to continually treating the symptoms while failing to cure the disease.

JFIIT experiments explored the potential of data links to overcome these deficiencies. Initial efforts to leverage the data links' potential to improve JCAS must focus first on passing digital target location to the attacking aircraft's weapons system and, second, on displaying the aircraft's aim point to the JTAC. These two enhancements will dramatically improve the speed and combat effectiveness of air-delivered fires and, simultaneously, minimize the potential for fratricide and undesirable collateral damage.

JCAS Terminal Attack Control Capability Gaps. While medium-altitude and standoff tactics help aircrews cope with today's threat, they aggravate the challenges in target acquisition and terminal attack control. JFIIT historical data confirms the impact of these visual limitations. During both All Services Combat Identification Evaluation Team (ASCIET) 2000 and JCIET 2002, aircrews were able to positively identify the target in less than one percent of attempts to employ ordnance. Likewise, under ideal conditions, terminal controllers were able to visually determine the medium altitude weapons aim points in only 45 percent of the CAS attacks in the JCAS JT & E Mini-Test 1 (February 1999) and in 67 percent of the CAS attacks in the Mini-Test 2 (June 2002). To frame JFIIT observations in the proper context, we first must understand the root cause of visually based terminal control deficiencies.

Gap No. 1: Aircrews cannot reliably identify the intended target. On the modern battlefield, an A-10 Thunderbolt 30-mm high-angle strafe attack probably provides the best opportunity for a fixed-wing attack pilot to visually identify a tactical target. The aircraft has a typical roll-in and engagement decision range occurring at approximately 9,600 feet. To put this in the perspective of what the pilot sees at this range, a T-72 tank appears smaller than the word "TRUST" viewed on a quarter held at arm's length.

At best, this target may be recognizable as a vehicle and possibly armored, but the characteristics that determine friend from foe cannot be reliably distinguished visually, even at this short tactical range. At a 6,000-foot firing range, the T-72 is barely wider than the two milliradian aiming index of the A-10 sight (2.56 mils).

Standoff weapon deliveries produce similar identification problems, even with the aid of aircraft sensors. A typical weapon's release slant range for a medium-altitude PGM attack is 26,000 feet. Using an onboard targeting pod with 20-power magnification, a T-72 on a cockpit display would be approximately the size of George Washington's head, using the same arm's length quarter comparison. Although this equates to a larger apparent target size, the gains in magnification are offset by a loss in detail due to the display's resolution and environmental factors of the increased range.

Gap No. 2: The JTAC cannot reliably determine the attacker's aim point. Increased release ranges also create a problem with visual acuity for the JTAC. His estimation of the weapon's impact point is based on his visual assessment of the aircraft's altitude, dive angle, airspeed, attack azimuth and anticipated release point and the weapon's ballistic profile.

While it may be possible for a controller to predict an aim point for a 30-mm strafe attack, this task is impossible for a Maverick launched from a three and one half- to six-nautical mile (NM) slant range or a global positioning system-(GPS)-guided munition dropped from a bomber flying 20,000 feet above the target. Assessing a "dot in the sky" dropping a "nonballistic" PGM with an unpredictable flight path, even in perfect meteorological conditions, forces the JTAC into an untenable "best guess" situation.

Effects on the JCAS Terminal Attack Control Process. These two capability gaps not only jeopardize the effective application of CAS, but also contribute to lengthy delays in delivering the necessary air power. Typically, target coordinates provide the initial cue for the aircrew to begin target acquisition. A talk-on process describing target area geographical features and target orientation/layout follows to help the aircrew during the search.

This talk-on process can be time-consuming and is prone to errors due to differences in perspective. For example, an aircrew may find a likely looking hot spot appearing near the target coordinates from the airborne perspective, which is beyond the ground controller's field of view or knowledge. Additionally, commonly found geographical features, such as multiple T-intersections, can cause aircrew and controllers to believe they are referring to the same target when, in fact, they are not.

Terminology frequently contributes to this confusion. When an aircrew reports it has acquired or identified the target it typically is indicating it has simply acquired a "blob" whose recognizable attributes and position generally match the description provided by the controller.

The JTAC then makes a "Cleared hot" call, believing the pilot has accurately identified the intended target. With clearance, the pilot releases ordnance on this blob, confident the controller has confirmed he is engaging the desired target. This scenario results in a high potential for ineffective missions, undesirable collateral damage or fratricide.

The Near-Term Solution--Tactical Data Links (TDLs). Digitally sharing continuously updated targeting information via fielded TDLs can mitigate the problems inherent in visually based terminal attack control. During JFIIT evaluations, participants have been encouraged to experiment and explore the practical application of TDLs in a robust data link architecture. Although data links support a broad range of [C.sup.2] messages, two specific TDL capabilities can leverage existing technology to overcome the two fundamental Type 1 terminal attack control deficiencies.

TDL Priority No. 1: Transmit target location (coordinates/elevation) directly to the aircraft's avionics and displays. An accurate target location integrated with the aircraft avionics is an aircrew's most useful cue to initiate its search for the target. While not directly addressing the deficiencies associated with visual terminal control, this data link significantly reduces cockpit workload and minimizes the multitude of potential format and data entry errors associated with the manual coordinate processing. In properly configured aircraft, the accurate target coordinates provide the aircrew a digital target mark in the form of a cross-hair position on a weapons video screen and designation cue in the heads-up display (HUD).

TDL Priority No. 2: Digitally share the attack aircraft's current sensor or weapons system aim point with the JTAG and [C.sup.2] systems. While a data link dramatically improves the speed and surety of communicating a target location, this capability alone does not ensure an aircrew can acquire and designate the correct target. A complementing and critical data link to close the loop is referred to as sensor point of interest (SPI).

SPI is a generic term describing the ability to share the attack aircraft's current sensor or weapons system aim point with the JTAC via a data link. In a stand-off weapons delivery, receipt of the SPI allows the JTAC to determine the aircrew's intended aim point and confidently declare "Cleared hot" or "Abort," as necessary.

TDL Use in JCAS Live Experiments. The TDL capability was successfully employed during JCIET 2002. In this experiment, a Marine Corps air officer had a TDL laptop terminal, joint surveillance and target attack radar system (JSTARS) workstation, unmanned aerial vehicle (UAV) video feed and appropriate radio frequency (RF) communications. In coordination with the Blue Force maneuver units, the air officer used JSTARS and UAV cues to detect possible enemy locations.

With an SPI-capable UAV, he identified an enemy tank (a T-72, in this case), extracted a rough coordinates and digitally transmitted a "9-line" brief to a TDL-equipped aircraft. The pilot cued his sensor to the steer point automatically generated from the data linked coordinates, refined his sensors to a suspected target hot spot and made an "SPI on" call.

The air officer then confirmed the SPI from the fighter and the UAV were on the same target. After a final check of the UAV video to confirm the target as a hostile T-72, the air officer made the "Cleared hot" call with high confidence, knowing that the hot spot seen by the aircrew was, indeed, the intended target.

The aircrew's post-mission comment, "This is too easy," highlights the dramatic improvement in speed and accuracy these two TDL capabilities bring to the JCAS terminal attack control process.

Other TTP possibilities quickly evolved as participants experimented with data links. An air officer performed a talk-on, steering the aircraft's SPI location: "Viper 51, you're looking too far south; bump your sensor 300 meters north up the dirt road ... that's good, right there." This transmission was followed shortly by, "Viper 51 is contact."

A JTAC also used the UAV SPI as a digital mark on a moving vehicle. Because target coordinates were rapidly changing, he directed the attack aircrew to "hook" (capture) the UAV SPI in lieu of giving target coordinates. The aircrews easily used the UAV SPI as a pointer to acquire the moving target.

In another TTP development, attack flight leads and wingmen employed SPI to rapidly sort and coordinate multiple aim-points to maximize their weapons effects on the first pass.

In a separate evaluation (JCAS JT & E Mini-Test 2), terminal controllers using stable SPI accurately confirmed aircraft aim points in 97 percent of all attacks without visually observing the attacking aircraft or target.

Defining Priorities, TDL applications for JCAS are receiving more attention as the number and type of TDL-capable aircraft increase. The services' program managers for platforms and systems struggle to reconcile priorities, based on differing perspectives and their investments in legacy systems. But it is imperative that joint TDL implementation efforts start with the digital transmission of target location and SPI-sharing capabilities.

Any data link implementation, even within a single system, presents many technological challenges. Add the complexities of assuring interoperability across many weapons systems developed by several vendors at the request of multiple services, and the challenge increases exponentially.

By prioritizing implementation of achievable capabilities to data link the target's location and aircraft's aim point, the services can realize immediate gains in supporting the maneuver force commander. Existing gateways, translator forwarders and operational TDLs can serve as the backbone of a much-needed interoperable capability. Challenges in JCAS transformation span the initial air request process, integration and coordination through actual attack and post-strike assessment.

The underlying goal always has been to put the right weapon on the right target at the right time to achieve the desired effects for the ground commander. In today's warfighting environment, TDLs can provide a near-term solution by enabling digital transmissions of target location and aircraft SPI to significantly increase combat effectiveness accompanied by a dramatic decrease in the potential for fratricide. Aggressive joint development, acquisition and implementation of these crucial TDL priorities will provide the tools to enable more effective terminal attack control.

Perry H. ("Pudly") Davis is a Senior Analyst on the Joint Fires Integration and Interoperability Team (JFIIT), Eglin AFB, Florida. He has more than seven years experience as a Joint Close Air Support (JCAS) subject matter expert in the All-Services Combat Identification Evaluation Team (ASCIET)/Joint Combat Identification Evaluation Team (JCIET)/JFIIT programs. His Air Force active duty experience includes serving as the Chief of Analysis in the Air-to-Ground Weapons Systems Evaluation Program in the 86th Fighter Squadron at Eglin; Chief of Weapons and Tactics in the 562d Tactical Fighter Training Squadron at George AFB, California; and Chief of Weapons and Tactics in the 81st Tactical Fighter Squadron at Spangdahlem Air Base, Germany. He is a 1988 graduate of the USAF F-4 Fighter Weapons School and F-4G Wild Weasel Instructor Electronic Warfare Officer.

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