Aerosol Particle Spectrometer with Depolarization and Fluorescence

An operational optical particle counter will be built, extensively characterized and evaluated that measures the size and shape of aerosol particles with optical diameter from 0.1 to 10 μm. This instrument will distinguish different species of dust and volcanic ash from other types of aerosol particles, and provide an estimate of the aerosol optical properties and produce compositional information related to a particle’s refractive index and shape. Some types of biogenic and organic aerosols will also be identified from the measurements.

The size, shape, refractive index and some compositional information of particles is derived from the measurement of light scattered in multiple directions, depolarization of the scattered light by aspherical particles, and the fluorescence by some species of biogenic and organic aerosols when excited by the 405 nm source laser.

The size, weight and power of the instrument will be optimized to facilitate operation on a wide variety of ground-based, airborne and ship-borne measurement platforms, including unmanned aerial vehicles.