A photoacoustic spectral absorption instrument with integrated calibration system

Light absorption by aerosols is a key component to atmospheric extinction, and affects a number of processes relevant to the Navy. Satellite and other remotely sensed measurements can be strongly impacted by aerosols, obscuring targets and/or confounding interpretation of data products. Directed energy applications, including weapon and communication systems, are also impacted by absorption, which affects processes such as thermal blooming. There is currently a lack of reliable, sensitive aerosol absorption instrumentation capable of operating in challenging field environments and at wavelengths needed for measurements relevant to the Navy, including in the infrared region of the electromagnetic spectrum. To address this need, we propose commercial development of a proven system based on photoacoustic technology, originally developed at NOAA and further enhanced by researchers at the University of Wyoming. The system is readily adaptable to the wavelengths of interest and has a proven track record for providing highly accurate, sensitive measurements of light absorption in the visible, including measurements from airborne platforms. Phase I of our effort focuses on de-risking the development by first evaluating the performance characteristics of several candidate optical systems (lasers, mirrors) that will be implemented in the existing Wyoming instrument hardware. We will also test a novel calibration approach that will greatly simplify operation of the instrument in the field by non-specialists, a critical step towards operational use and broader commercial applications. Finally, in the option period we begin transitional work towards a new instrument prototype that focuses on improving the ability of the instrument to measure particles over a broad size range and simplify temperature control.