Apparatus and method for in-flight detection of airborne volcanic ash

摘要

A method of optically determining the presence of volcanic ash within a cloud comprises emitting a circularly polarized illuminating beam within a cloud (102) and analyzing backscatter light to identify the presence of volcanic ash within the cloud (104). The method may further include determining the degree to which the cloud has altered the polarization state of the emitted beam. The index of refraction of the backscatter light and the opacity of the backscatter light may also be analyzed.