TABLE OF CONTENTS Some fundamentals of radio waves from Faraday, Maxwell, and Hertz
Putting together a simple radar and discussing its principal par ts
Deriving the radar range equation from first principles
Discovering special features of surveillance and tracking radars
Radar is an acronym for RAdio Detection And Ranging. Before we develop the principles of radar, we will review the characteristics of radio waves.
Radio waves occupy a portion of the electromagnetic spectrum from frequencies of a few kilohertz (that is, a few thousand cycles per second) to a few million megahertz (>10 12 cycles per second). The total electromagnetic spectrum embraces all the frequencies to cosmic rays, beyond 10 16 megahertz (MHz). Radio waves represent less than one-billionth of the total spectrum (see Appendix 2).
Although electromagnetic energy can be described either as waves or as quanta, the lower frequencies are much better suited to explanations by wave theory. Radio waves are certainly thought of in those terms.
The definitive experiments in electromagnetism were performed by Michael Faraday in a period of ten days in 1831 [ Encyclopedia Britannica , 1984, Vol. 7, p. 174; Williams, 1971, pp. 535 537]. Using Faraday s work as his foundation, James Clerk Maxwell succeeded, by the early 1860s, in synthesizing the properties of electricity and magnetism into a set of equations that achieved a unified theory for electromagnetics [ Encyclopedia Britannica , 1984, Vol. 11, p. 718; Everitt, 1974, pp. 204 217].
In Maxwell s...
