KPR is a compact Ka-band Probe Radar and Radiometer for measuring vertical profiles of reflectivity and Doppler velocity. Key features of the instrument are: a pair of flat-plate array antennas pointing in the zenith and nadir directions, 10 W peak power solid state transmitter amplifier and a low-loss switch network. KPR includes an integrated noise source and ambient load for sky brightness temperature measurements and radiometric calibration of its receiver. The instrument is packaged to install in a standard (6″ ID x 24″ L) PMS probe canister.