9S52 Polyana-D4 ASU (Russian: АСУ зенитной бригады 9С52 «Поляна-Д4») is a Soviet/Russian automated command and control system for air defence troops. May act as an upper level command post (CP) of the SAM brigade including S-300V as well as the 9K37 Buk complex. And also other means, including aircraft. Mass production of the system organized at the Minsk Electromechanical Plant (currently GNPO Agat), but later transferred to Penza, former Minradioprom factory. In service since 1986. Polyana-D4 is a substantial remake of 9S468M1 Polyana-D1, development by NIIAA.