Patent attributes
Apparatus and associated methods relate to differentiating ice accretion caused by different supercooled water droplets on an airfoil of an aircraft. A sensor having a sensing surface region is mounted at a mounting location of the airfoil such that the sensing surface region is flush with a surrounding adjacent surface of the airfoil. Water particles of sizes less than or equal to a predetermined threshold do not impinge the sensor surface region at the mounting location when the aircraft is in flight. A sensor driver provides an excitation signal to the sensor. A signal detector detects a sensor signal responsive to the provided excitation signal. The sensor signal is indicative of water particles exceeding the predetermined threshold impinging the sensing surface region. In some embodiments, the sensing surface region is mechanically coupled to a resonant cavity. In other embodiments, the sensor is a surface resistance sensor configured to sense surface resistance.
