19.1 INTRODUCTION

Radar guided missiles represent one of the most widely used applications of the radar art, yet one about which much less has been published in the open literature than about other, more "conventional" radars. There is no nonmilitary use of this part of radar technology, and much of the detailed data is still classified. However, drawing solely on the unclassified published data permits at least a tutorial overview of radar guidance to be presented in this chapter.

Guided missiles can be characterized in several ways, ^{1 4} based on their mission, type of guidance, sensing wavelength, source of guidance energy, etc. The discussion here will narrow down to the particular radar homing types which form the vast majority of operational systems.

Based on their use, missile systems can be categorized as surface-to-surface, air-to-surface, surface-to-air, and air-to-air. The types of guidance are inertial, map-following, command, beam-riding, and homing. Types other than inertial can use the broadest range of the electromagnetic spectrum, from radio frequencies (RF) through infrared (IR) to the visible spectrum and beyond, to perform the guidance function.

Within these general categories, the surface-to-surface types [especially the intercontinental ballistic missile (ICBM) and the shorter-range ballistic] are usually inertially guided and fall outside the scope of this discussion. The primary exception is the antiship missile, which uses radar guidance and may be surface-(as well as air-) launched.4 ^, 5 The main users of radar guidance are the air defense systems surface-to-air or air-to-air.