9.1 INTRODUCTION

In the 1990s, as stealth technology continues to mature and move from the research and development phase to production, it will become ever more difficult to detect aircraft and cruise missiles with conventional radars. Although both airborne and ground-based radars may undergo major design changes for detecting and acquiring low radar cross section vehicles, adjunct sensors must also be integrated into any future surveillance system to increase the probability of detection.

Present surveillance and tracking systems (E-2C, E-3A) are able to detect threat aircraft (fighters, bombers) well past 200 miles. A challenge for future airborne early warning (AEW) platforms is the detection of low observable aircraft and cruise missiles at low altitude and at long ranges.

Selection of a sensor suite that meets the threat will be the driver in selecting a suitable aircraft platform. The majority of today's airborne, ground, and naval platforms typically rely upon one or two types of sensors to provide threat warning and fire control information. These singular sensors normally detect, process, and identify threats/targets by operating in an unusually well-defined, often very narrow portion of the electromagnetic spectrum.

Electronic support measures (ESM), identification, friend or foe (IFF), and communications are common adjunct sensors and will be covered briefly in this chapter. Infrared (IR) has great potential because of emerging infrared technologies; however, atmospheric attenuation is high and its performance under adverse weather conditions is marginal. Electro-optical (EO) or low light level...