Payload technologies and applications for uninhabited air vehicles (UAVs)

After more than 50 years of limited niche applications in such roles as aerial targets, UAVs have recently emerged as major aerospace platforms for both military and civilian uses. This is due to three fundamental breakthroughs: (1) UAVs have begun to achieve reliability levels which allow routine operational use, (2) payload technologies have matured to the point where extremely useful functions can be accommodated within the weight, volume and power constraints of small airplanes, and (3) evidence is mounting that UAVs can do many tasks better and more affordably than manned aircraft. In many ways, UAVs compete with space systems for equivalent functions, often with the advantage of persistence over an area of interest at far closer range than a geostationary satellite. This paper surveys some of the major electronics developments which contribute to this resurgence. Among the topics covered are UAV architectures; imaging sensors, including synthetic aperture radar (SAR) and infrared/electro-optical (IR/EO) cameras; communications and data link systems; specialized sensors for such things as chemical detection and RF spectrum surveillance; and onboard processing. In all of these, recent system designs demonstrate levels of performance, e.g., SAR resolution and image processing time, comparable to or better than those achievable a few years ago only in systems costing one to two orders of magnitude more. The ways in which these payloads support military missions such as surveillance and commercial operations such as communications relay and earth resources sensing are reviewed. Finally, some projections are presented about important trends in both payload technologies and system applications.