What characterizes pulse modulation in radar?

Pulse modulation in radar is characterized by short bursts of radio frequency (RF) energy. This technique is essential for radar systems as it allows for the transmission of energy in discrete, controlled pulses rather than a continuous wave. This pulsing enables the radar to measure the time it takes for the transmitted signal to reflect off an object and return to the radar system, aiding in distance and speed calculations.

The use of short bursts enhances the system's ability to differentiate between multiple targets and reduces interference from continuous signals. It allows for better resolution and more effective target detection by providing a clear "on" and "off" state for the RF energy.

Continuous RF transmission, while a valid method of communication, does not allow for the measurement of distance or separation of targets as effectively as pulse modulation. Fixed frequency emissions and constant frequency deviations are characteristics associated with different kinds of modulation techniques, which typically do not utilize the time-based advantages that pulse modulation provides in radar applications.