Research Brief

As demonstrated during Operation Desert Storm, U.S. air power has become adept at destroying mechanized ground forces. By contrast, the U.S. military has found it much more difficult to detect and engage lighter forces in complex terrain, such as urban areas and triple-canopy jungle. Confrontations with light forces will be more likely as the United States becomes increasingly involved in peacekeeping and enforcement operations. The Air Force has begun to consider how newly developed technologies might improve offensive capabilities against such forces.

A recent RAND study, Enhancing Air Power's Contribution Against Light Infantry Targets, by Alan Vick et al., discusses the challenges posed by light infantry opponents and presents new operational concepts that may help meet such challenges. After exploring the signatures and vulnerabilities of typical light forces, the study focuses on advances in sensor technologies that have the potential to detect these signatures. The authors then describe how such sensor technologies might be combined with platforms, weapons, and tactics. They conclude by evaluating twelve operational concepts and recommending that the Air Force turn a number of promising technologies into fielded capabilities.

Confronting Light Infantry Forces

During previous confrontations with light forces in various theaters and conflicts, U.S. light infantry typically did the brunt of the work while air power played an important and sometimes decisive supporting role. In most situations, friendly ground forces—or air liaison officers located with them—detected and identified ground targets for attacking aircraft. At times, especially in Vietnam, the airborne Forward Air Controller (FAC), flying low and slow in vulnerable propeller aircraft, also played a vital detection role. Airborne FACs, however, had no sensors beyond their eyes and binoculars. Consequently, while FACs were effective at detecting targets in open areas, attacking aircraft had to depend on ground observers to locate and identify targets in thick woods.

Furthermore, while air operations in support of engaged ground forces were often successful, independent air operations against non-engaged enemy light forces were much less effective, primarily because sensor limitations prevented such forces from being detected in foliage and at night. These and other limitations have not yet been overcome, and the Air Force's ability to detect, identify, and attack light infantry forces in dense foliage, rugged terrain, and urban areas is not significantly better now than it was during the Vietnam War.

Signatures

Enemy light units engaging in sabotage, assassinations, patrols, ambushes, and harassment operations usually exploit darkness, terrain, and foliage for protection from attack. However, such units produce signatures—visual, chemical, infrared, and others—that can be detected by a variety of sensors. Clever adversaries can minimize their signatures and fool some sensors, but they cannot hide all their signatures. Usually, light forces must choose between achieving operational objectives and minimizing risk of exposure. More forces, more movement, and more equipment translate into more signatures that various types of sensors can detect.

Sensor Technology

Recent advances in detector technologies and data processing have combined to make sensors vastly more capable than those of the past. Originating primarily in DoD programs to detect armored vehicles, many of these technologies have great potential against light infantry as well. Foliage-penetrating radar, hyperspectral image processors, and advanced thermal imagers would be especially effective on intelligence-gathering airborne platforms. Seismic, magnetic, acoustic, and low-light television (LLTV) technologies appear to hold the greatest potential for air-dropped ground sensors that would transmit information to fusion and control centers.

No single sensor, however, can detect all infantry signatures under all operational conditions. Consequently, the use of multiple sensors is the key to achieving robust performance and obtaining acceptable probabilities of detection and identification under varied tactical conditions. Placing such sensors on the same airborne platform would be especially effective, because it would enable operators to look at a target in several different ways before it disappeared from view.

Advances in data-fusion software and in multispectral sampling suggest that it will be possible to produce a composite image of targets within seconds or minutes. By quickly providing commanders with a reliable multi-dimensional portrait of the battlefield, this composite-image approach should enable U.S. forces to identify and attack hostile targets when they are most vulnerable.

Unmanned Aerial Vehicles

To achieve the required quality of images, sensor platforms will, in many cases, have to loiter at altitudes and ranges within the envelope of manportable air defense systems (MANPADS). Consequently, the Air Force must find ways of carrying sensors to altitudes well below 10,000 feet without suffering high attrition. Of possible solutions, low-cost unmanned aerial vehicles (UAVs) appear to offer the greatest potential. Multiple UAV designs, each optimized for a particular operating environment, would enable sensors for all types of surveillance missions to be deployed effectively. The continued miniaturization of electronic components and developments in lightweight optics suggest that high-resolution sensors can be deployed in very small airframes. Such UAVs can probably be made cheaply enough that attrition would not be a significant constraint on their use.

Alternative Operational Concepts

To illustrate potential applications of the proposed technologies, the RAND study developed a near-term and far-term operational concept for each of six highly probable combat tasks. The tasks, which include locating and destroying light forces in woods and in urban environments, have four features in common:

  • They require a tightly integrated reconnaissance/surveillance/battle management system that can pass cueing from a broad-coverage, low-resolution sensor to increasingly higher-resolution sensors.
  • All use a mix of sensor platforms, ranging from high-altitude manned aircraft to unattended ground sites.
  • All require that high-resolution sensors (for target identification) operate well within the MANPADS envelope.
  • Most rely heavily on UAVs because of their superior endurance, survivability, and expandability.

The near-term concepts involve only those systems available now or within five years; the far-term concepts are based on plausible applications of known technologies that will require more time to mature.

Recommendations

The authors' analysis indicates that these operational concepts could significantly enhance air power's ability to detect, identify, and attack light infantry targets. All the concepts require the development and acquisition of new sensors, unmanned aircraft, and other systems, but the cost of these systems would be very low. Although the technical feasibility of several long-term concepts remains to be demonstrated, the Air Force should be able to conduct four of the six combat tasks within a decade if it chose to pursue the development and acquisition programs.

The authors recommend that the Air Force convene a Light Adversaries Conceivers' Action Group (CAG) to address the implications of the suggested operational concepts and to propose additional tests, exercises, and evaluations that would convince a major user—such as the Air Combat Command—to turn these concepts into fielded capabilities. The Air Force could make a significant contribution to virtually all scenarios involving adversary light forces if it embraces this mission area and pursues the possibilities described in the study.

Research conducted by

This report is part of the RAND Corporation research brief series. RAND research briefs present policy-oriented summaries of individual published, peer-reviewed documents or of a body of published work.

The RAND Corporation is a nonprofit institution that helps improve policy and decisionmaking through research and analysis. RAND's publications do not necessarily reflect the opinions of its research clients and sponsors.