What is "monopulse radar"

n. any radar that is capable of estimating the position of a target based on the return of a single pulse from a cluster of simultaneous beams

Monopulse radar is a radar system that compares the received signal from a single radar pulse against itself in order to compare the signal as seen in multiple directions, polarizations, or other differences. The most common form is an adaptation of conical scanning radar which compares the return from two directions to directly measure the location of the target. This avoids problems in decoding conventional conical scanning systems, which can be confused by rapid changes in signal strength. The system also makes jamming more difficult. Most radars designed since the 1960s are monopulse systems.