History of Development of the MU (Middle and Upper Atmosphere) Radar, the First Large-Scale Atmospheric Radar with Two-Dimensional Active Phased Array Antenna System

The MU radar was built in 1984 as the first large-scale MST (Mesosphere, Stratosphere, and Troposphere) / IS (Incoherent Scatter) radar with a two-dimensional active phased array antenna system by Kyoto University with the collaboration of Mitsubishi Electric Corporation. IEEE Milestone was dedicated to the MU radar in 2015. This article describes the history of development of the MU radar, its historical and technological significances, influence to the subsequent system, continuous research and development towards the future, and the milestone dedication.