This Small Business Innovation Research (SBIR) Phase I project proposes the development of a universal single-channel polarimetric receiver. A novel polarization measurement technique based on a spinning phase plate makes it possible to measure all four Stokes parameters of the incoming radiation with the use of one receiving channel only, while the conventional technique requires at least three channels for the same purpose. The major application of the proposed device is the in-flight detection of clouds that pose icing hazard. Measurement of the Stokes parameters of the radiation emitted by<br/>(radiometry) or reflected from (radar) these clouds proved to be useful for the determination of their potential danger. The device can operate as both a stand-alone radiometer and as the receiver of a radar system.<br/><br/>The proposed polarimetric receiver is compact, capable of detecting icing conditions with excellent sensitivity and resolution, and manufacturable within existing infrastructure.<br/>There is an urgent need for such a low-cost and high-performance product for detecting potentially hazardous clouds along the flight paths, especially for helicopters, commercial commuter aircraft, and light, private, unpressurized aircraft.