Document created: 14 October 2003
Air University Review,
November-December 1973
The ability of tactical fighters to penetrate enemy defenses and to acquire, identify, and destroy ground targets has been a keystone of success in every United States aerial campaign from World War II until the present. To improve its air-to-ground strike capability, the U.S. Air Force has devoted considerable development effort and resources to the penetration of defense, accuracy of delivery, and lethality of munitions.
An equally vast area of research and development expenditures has been for aids to target identification under adverse visibility conditions, i.e., night and/or bad weather. Little attention has been focused on the problem of target acquisition under good visibility conditions.
My experience over a five-year period in the F-105, including 145 combat missions in Southeast Asia, has convinced me that simply finding the target during the daytime is our most acute problem. Discussions with people of greater and more varied experience confirm that rapid, certain target detection and identification are the dominant factors in the success of all air-to-ground attacks.
The Wright brothers began aerial flight observing the ground from very low altitude at a very slow speed and with a view almost completely unobstructed by the airframe. Over the years, visibility of the lower hemisphere has become almost completely obscured by aircraft structure, and enemy defenses have necessitated higher speeds and higher altitudes. As an example, from an F-4 in level flight at 20,000 feet, the pilot cannot see the ground for approximately five nautical miles on either side of his flight path or approximately ten nautical miles ahead of his position. The viewing area for the crew member in the rear seat is even more restricted. To acquire and identify a target within the obscured area, the pilot must either fly an offset approach to the target or must change aircraft attitude by altering pitch and bank. The offset approach restricts flight path planning flexibility, and the maneuvering disrupts tactical formations, alerts the enemy, and increases exposure to his defenses. Higher altitudes not only widen the area of obscuration but also increase slant ranges. At slant ranges greater than 8000 feet (the nominal minimum weapon release range in a moderately defended area), it is difficult to acquire a truck target, even one in open terrain. Given ideal optical conditions of illumination and contrast, visual acuity is still a function of the angle that the target subtends at the aircrew’s eye. Simply detecting a truck is only part of the problem. Once found, a truck must be observed in sufficient detail to ascertain if it is in commission, has been previously damaged, or is a decoy.
The employment of standoff weapons demands acquisition and identification of targets at even greater ranges. In environments of unsuppressed antiaircraft defenses, optimal employment of standoff weapons necessitates standoff ranges in excess of 15,000 feet. Probability of detection for a target of opportunity from this range is extremely low. When operating against prebriefed targets whose locations and appearances are known and have been studied by the strike crew, the detection probability is only slightly enhanced.
Subtended visual angles and contrast of the complete target area may be sufficient to allow detection, identification, aircraft positioning, and weapons release beyond range of ground defenses. However, target acquisition and identification can still be impossible if the target scene is complex and accurate target designation requires isolating the target from surrounding background detail. Currently, the United States is spending a considerable sum on standoff and terminally guided weapons. Extreme accuracies are possible, but rapid, positive visual acquisition of targets at the required ranges severely limits full exploitation of these potentials.
In order to extend our visual acquisition capabilities, perhaps we need to borrow some concepts from Mother Nature. She has provided a solution to acuity limitations while at the same time retaining field-of-view. The hawk has coverage of almost the entire visual sphere with up to eight times the visual acuity of man. Hawks have other visual advantages over man: high sensitivity to motion of an object, extremely rapid accommodation, and a color-filter system to aid in identifying prey.
We need to borrow from this work of Nature. U.S. tactical fighters need a hawk-like system that provides an unrestricted view of the ground and high visual acuity.
Recent advances in the art of electrical-optical (E/O) devices have led to capabilities that could provide such a system. An E/O device is essentially a TV camera looking through a telescope. The target image is optically enhanced, received by a vidicon tube, converted to an electrical signal, routed to the cockpit, and displayed to the pilot in conventional TV format.
Although radar and infrared devices have their utility in detection, they do not provide the operator a sufficient bandwidth of information for long-range identification of small targets. Given the premise that the majority of tactical strikes are conducted in conditions allowing the use of E/O devices, the emphasis on radar and infrared development appears out of proportion.
Electrical-optical devices permit scene magnification, longer stabilized viewing times, and enhanced contrast. Therefore, E/O techniques permit target acquisition and identification at ranges far exceeding those of the unaided human eye. These E/O devices can accomplish this while retaining image fidelity exceeding radar or infrared. These factors suggest the general desirability of an aircraft subsystem such as a trainable E/O telescope with a large off-boresight slewing capability. Such a video telescope system must have high magnification for good resolution of the explicit target area but must be coupled with a wide field-of-view optical device. The operator could use such a system in the same fashion as he uses his own eye. The low resolution, wide field-of-view (analogous to periphery of eye) would be for orientation, search, and initial acquisition of a point of interest. The high resolution, narrow field-of-view would then be pointed at these areas of the wide field-of-view that merit closer examination (analogous to the fovea of the eye).
This scheme would permit launch of extended-range E/O-guided weapons on targets that have been detected and identified by the pilot, using his video telescope device. If a laser receiver and/or a laser illuminator were also coupled to the gimbaled tracking telescope, the system would be usable for delivery of laser-guided munitions. It could be designed for cooperative missions, wherein the forward air controller provides the illumination or it is provided by the strike aircraft. Reflected laser spot detection capability would enhance its discrimination and also make it usable during night or adverse weather.
Incorporation of a large field-of-view, high-accuracy aid could provide the additional benefits of an excellent system to guide visually directed munitions or to point other sensors or designators precisely. From the defensive standpoint, the system would provide air-to-air identification at ranges sufficient to allow more optimum tactical offensive or defensive decisions and reactions.
Such a system would offer major new capabilities in the operations and intelligence fields. The video display for the aircrew can be preserved on video recording tape and played back immediately on a TV monitor after the aircrew is on the ground. This capability approaches near real-time reconnaissance for the tactical user by reducing the need for special photo reconnaissance missions, which require postflight image development or processing. Moreover, present data link technology will allow fighter aircraft video to be telemetered direct to ground monitor stations, thus providing true real-time, positively controlled reconnaissance capability.
Other advantages of the high-acuity viewing system include improved weapons release systems, improved sights, and on-the-spot battle damage assessment. The reduction in number of sorties resulting from these improvements, plus reduced attrition rate resulting from increased standoff capability, indicates the system would be highly cost effective. While initially oriented toward daylight/clear air mass conditions, visual acquisition at night or through partial obscurations must not be ignored. Present developments in E/O systems for visual capabilities under poor viewing conditions are promising and are an obvious follow-on. However, their development should not delay incorporating a basic daylight/good-visibility system. The E/O technology for such a system is here. Alternate versions of the required image format and appropriate operator-to-sensor coupling schemes are under investigation but on a very small scale. The mechanical and aerodynamic considerations of sensor locations are quite straightforward, but they must receive early attention. Indeed, the requirement for a high-acuity, large field-of-view system must be emphasized and provided for during the conceptual phase of aircraft design.
In summary, a video telescopic device will greatly improve aircrew ability to acquire, identify, and destroy targets at much longer ranges. It will permit launch of E/O-guided weapons at increased standoff ranges. It can be readily adapted to the delivery of laser-guided munitions. Moreover, this capability will restrict the enemy’s freedom of movement when U.S. aircraft are in the area. This capability can provide actual real-time E/O reconnaissance from high-performance tactical fighters during the entry, attack, and egress phase of strike operations.
The changing nature of tactical warfare demands improved target acquisition and identification to exploit greatly improved weapons in the face of harsh interceptor, surface-to-air missile, and antiaircraft gun defenses. Improved standoff capabilities will lower combat attrition while increasing force effectiveness. In light of the continuing Soviet weapons and technological momentum, we must constantly strive to improve our tactical air power. Daytime, good-weather target acquisition, identification, and attack are our primary mode of tactical operation. We lack capability in this vital mission area. Great strides can be made quickly at relatively low cost and low risk by skillfully integrating current optical, electrical-optical, infrared, and laser technologies in our fighter aircraft. This needs to be done now!
Wright-Patterson AFB, Ohio
Major Dan Eliason (M.S., University of Southern California) is a behavioral scientist and project manager with the Aerospace Medical Research Laboratory, Wright-Patterson AFB, Ohio. His previous assignments include Flight Commander, 23d TFW, McConnell AFB, Kansas; and tactics officer, instructor pilot, and editor of the 388th TFW Tactics Newsletter, Takhli, Thailand. In addition to being an F-105 pilot, Major Eliason has served as an F-101B radar intercept officer.
Disclaimer
The conclusions and opinions expressed in this
document are those of the author cultivated in the freedom of expression,
academic environment of Air University. They do not reflect the official
position of the U.S. Government, Department of Defense, the United States Air
Force or the Air University.
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