Page 35 - Fundamentals of Radar Signal Processing

CHAPTER 1

Introduction to Radar Systems and Signal

Processing

1.1 History and Applications of Radar
The word “radar” was originally an acronym, RADAR, for “radio detection
and ranging.” Today, the technology is so common that the word has become a
standard English noun. Many people have direct personal experience with radar

in such applications as measuring fastball speeds or, often to their regret, traffic
control.
The history of radar extends to the early days of modern electromagnetic
theory (Swords, 1986; Skolnik, 2001). In 1886, Hertz demonstrated reflection of
radio waves, and in 1900 Tesla described a concept for electromagnetic
detection and velocity measurement in an interview. In 1903 and 1904, the

German engineer Hülsmeyer experimented with ship detection by radio wave
reflection, an idea advocated again by Marconi in 1922. In that same year,
Taylor and Young of the U.S. Naval Research Laboratory (NRL) demonstrated
ship detection by radar and in 1930 Hyland, also of NRL, first detected aircraft
(albeit accidentally) by radar, setting off a more substantial investigation that
led to a U.S. patent for what would now be called a continuous wave (CW)
radar in 1934.

The development of radar accelerated and spread in the middle and late
1930s, with largely independent developments in the United States, Britain,
France, Germany, Russia, Italy, and Japan. In the United States, R. M. Page of
NRL began an effort to develop pulsed radar in 1934, with the first successful
demonstrations in 1936. The year 1936 also saw the U.S. Army Signal Corps
begin active radar work, leading in 1938 to its first operational system, the

SCR-268 antiaircraft fire control system, and in 1939 to the SCR-270 early
warning system, the detections of which were tragically ignored at Pearl
Harbor. British development, spurred by the threat of war, began in earnest with
work by Watson-Watt in 1935. The British demonstrated pulsed radar that year,
and by 1938 established the famous Chain Home surveillance radar network that
remained active until the end of World War II. They also built the first airborne
interceptor radar in 1939. In 1940, the United States and Britain began to

exchange information on radar development. Up to this time, most radar work
was conducted at high frequency (HF) and very high frequency (VHF)
wavelengths; but with the British disclosure of the critical cavity magnetron
microwave power tube and the United States formation of the Radiation
Laboratory at the Massachusetts Institute of Technology, the groundwork was