Effects of turbulence on laser beam position

If a laser beam travels through a medium with constant refractive index, then the travel path will be a straight line from source to receiver. If the medium does not have a constant refractive index, then the beam will be diffracted. The lower atmosphere represents this latter case since temperature gradients near the Earth's surface generate turbulence that results in random fluctuation in the refractive index of the atmosphere. As a consequence, a laser beam traveling through the lower atmosphere will be diffracted from the intended target. This diffraction is a random phenomenon that is difficult to model and must be analyzed using statistical tools. By using a heated water column to simulate the lower atmosphere, this research has shown that turbulence based models can be improved by first establishing a reference that is used for comparison and statistical purposes.