Laser Sensor for High Sensitivity Atmospheric Absorption Measurements

Development of a high energy laser weapon for point defense of Navy surface ships requires increased knowledge of mechanisms leading to thermal blooming during propagation in the marine atmosphere. Specifically, more detailed knowledge of absorption by water aerosols is needed. Recent research has shown that current marine atmospheric aerosol models are most applicable for the open ocean; however, the models can have significant errors near land where continental dust, soot, and surf zone aerosols modify the nominal free ocean distribution. Physical Sciences Inc. proposes to develop a low power, solid state laser-based sensor suite for measuring the absorption arising from both the gas phase and aerosol components of the atmospheric marine boundary layer. Our approach couples an all solid state laser source with photoacoustic detection to create a spectrometer capable of measuring absorption coefficients as small as 10-4 km-1. In the Phase I program, we will develop a complete system design for a sensor suite capable of shipboard deployment. In the Phase II program, we will fabricate, test, field demonstrate, and deliver the system designed in the Phase I program.