The MU (middle and upper atmosphere) radar of Japan is a 46.5-MHz pulse-modulated monostatic Doppler radar with an active phased array antenna which consists of 475 crossed yagis. This system has been used primarily, since its initial observations with a partial system in 1983, to observe back-scatter from irregularities in the atmospheric index of refraction in the mesosphere, stratosphere, and troposphere (MST radar). However, this system was also designed to be able to observe the incoherent scattering (IS) from ionospheric plasma as well. We report here the capability of this system for IS measurements. This paper describes the observational technique employed for MU radar IS measurements, examines the expected accuracy of the plasma parameter measurements, and presents sample results to demonstrate the current capability.