In chapter 9, the subject is pulsed operation of the radar. Pulsed radar operation started in 1924. Today almost all radars are pulsed radars. In this chapter you will learn why pulsed radars are used. You will also cover the meaning of energy and power in radar terms. We will cover the basics of how the radar "waveform" is designed, that is, what is the width of the pulses, the spacing between pulses, and the modulation on the pulses.