Fundamentals of multibeam radar design principles, their basic operation modes and signal processing algorithms, potential characteristics when operating as part of security systems are considered. Their capabilities are shown when detecting low-speed small-sized targets, as well as when solving meteorological problems. Algorithms for signal processing, methods for generating requirements for functional units and software are described. The structure of programs for calculation of characteristics and simulation modeling is presented. For specialists involved in radar surveillance systems and security systems. It can be useful for students and graduate students studying in the relevant disciplines.