TABLE OF CONTENTS Florent Christophe
The capability of detecting moving objects in the environment of antennas radiating electromagnetic waves was anticipated early after the experimental evidence of such waves, thanks to Heinrich Hertz in 1886. Practical applications of radar (radio detection and ranging), i.e., the detection of vehicles and estimation of their position were demonstrated as early as the 1920s in France and Germany. The development of radar was then made possible by the availability of a microwave pulsed power oscillator, the magnetron (a derivative of which was mass produced starting in the 1970s for microwave ovens).
The importance of radar was fully recognized following its role in defending Great Britain against air attacks during World War II. Much public and industrial research funding was then invested in the United States and various European countries for solving technological issues and bringing radar to its present wide range of applications. These applications, which include geophysics, meteorology, remote sensing, air traffic control, and acquisition of military targets, come from the long-range all-weather sensing capability of radar.
If the beam radiated by a directive antenna such as a parabolic dish illuminates an object, some of the incident energy is backscattered and can be detected in a receiver connected to this same antenna. The direction of the beam and the round trip time delay between the transmitted and the received waveform-usually a repetitive pulse-are used to estimate the location of the scattering object.
Let
