Passive Optical Remote Sensing of Wind Velocities and Turbulence by Spatiotemporal Analysis of Image Distortions of Random Scenes

Northwest Research Associates, Incorporated, Seattle WA

Investigators

Abstract

The goal of the project is to develop, apply, and field-test methodologies to exploit spatiotemporal distortions of dual-telescope, optical image sequences of naturally illuminated, random scenes for the retrieval of range-resolved cross-wind velocities and turbulence statistics. The investigators will use random, natural surfaces with rich optical texture, such as bare mountain faces, hillsides, and canyon walls, which are ubiquitous in the American West. The sun and the moon will serve as light sources by day and by night, respectively. The availability of inexpensive, scalable, multi-purpose techniques and systems for passive optical remote sensing of the atmospheric boundary layer will benefit society in several areas, including weather monitoring and forecasting; air-quality monitoring and forecasting; cross-wind monitoring at highways, airport runways, and rocket launch sites; and wind sensing in support of wind-farm operations. The project will provide resources for mentoring a postdoctoral researcher and a graduate student, contributing to science, technology, engineering and mathematics (STEM) education and educator development. The study will use pairs of synchronized image sequences collected with two digital cameras mounted at two, laterally spaced, large-aperture telescopes pointing at the same target area. Target distances will range from hundreds of meters to tens of kilometers. Limited-visibility effects due to Rayleigh and non-Rayleigh scatter will be negligible for short ranges but are expected to play an important role for longer ranges. The proposed research will combine observational, computational, and theoretical methodologies from (1) atmospheric turbulence and boundary layer meteorology; (2) wave propagation through atmospheric turbulence; (3) atmospheric radiative transfer of visible light; and (4) imaging physics of coherent and incoherent light. The research will integrate, apply, and test concepts and hypotheses that are traditionally addressed separately in different science and engineering disciplines.