The millimeter wavelength cloud radar (MMCR) systems probe the extent and composition of clouds at millimeter wavelengths. The MMCR is a zenith-pointing radar that operates at a frequency of 35 GHz. The main purpose of this radar is to determine cloud boundaries (e.g., bottoms and tops). This radar will also report radar reflectivity (dBZ) of the atmosphere up to 20 km. The radar has a Doppler capability that allows measurement of cloud constituent vertical velocities.