Atmosphere Turbulence Profiling Laser System (TURPLAS)

Atmospheric turbulence is the dominant factor affecting the spatial structure of a laser beam propagating in free space, resulting in beam jitter and a decrease of the energy density on the target. This MetroLaser Phase I proposal describes an innovative approach to measuring the strength of the atmosphere turbulence along a line of sight. The method employs a laser system combined with a phase conjugate mirror to generate Rayleig/Mie scattering guide stars. The innovation is in coherent detection of the ultra-low level radiation intensity of the guide star, its amplification, and registration of its spatial-temporal distribution. This information enables profiling the Cn2 parameter along the beam path, estimating Fried parameter, isoplanatic angle, and the Rytov parameter. The advantage of the proposed system lies in an ultra-high sensitivity and spatial/temporal resolution. During Phase I, we will perform an analysis of the phase-conjugate-mirror-based laser system, and proof-of-concept experiments. During Phase II, we will extend the performance capabilities of the proposed laser system, design and build a brass board for verifying and optimizing the predicted system performance, demonstrate the system, and determine its operational envelope.