3.1 INTRODUCTION

Since the first days of armed conflict, the benefits of a high vantage point have been recognized. At first it meant a pair of eyeballs in a tree; then it was a long glass from the top of a mast, followed by field glasses from a balloon. The sensor men's eyes, aided by glass remained the same for a long time. But early in the twentieth century the "platform" became more mobile, reached higher, and improved the detection range. The fixed wing aircraft had become the new surveillance platform.

Eyes have long since been replaced by more sophisticated sensors. World War II brought the advent of radar to aircraft and more recently, long-range infrared (IR) sensors and ultrasensitive optical detectors have been brought into use. Aircraft have become more complex as well; but to keep things in perspective, the aircraft platform does nothing more than the tree of old. It places the sensor in the optimum position to take advantage of its capabilities. Naturally, it does the job better because it uses the advantages of very high altitudes, long range, speed, and mobility. It should be noted, however, that even that earliest platform (the tree) had an advantage over the most modern aircraft it still wins when it comes to endurance.

Thus, we see that newer and fancier is not always ideal. The platform must be tailored to the mission. Even today the older platforms such as balloons are still in use and...