CloudSat is a satellite-based 94 GHz Cloud Profiling Radar (CPR) mission designed to measure the vertical structure of clouds and precipitation from space; unlike passive sensors, its active radar can penetrate through cloud layers to reveal internal vertical structure, and it is sensitive enough to detect a wide range of cloud types (including thin cirrus as well as deep convective clouds and the internal structure of hurricanes), with its reflectivity profiles allowing meteorologists to distinguish between different cloud types based on their characteristic radar backscatter signatures.