Light Deflection Wind Mapper

A new optical sensor to map wind speeds with millimeter resolution will be detailed and demonstrated. The instrument works by detecting the deflection of light by gas density fluctuations. The measurement can be either spatially averaged over the propagation path of the beam or spatially localized in three dimensions by monitoring the cross-correlation between the signals from two intersecting laser beams. This technique does not depend on scattering from particulates, so nothing need be added to the flow. The measurement can be calibrated absolutely and the transverse flow velocity is determined from the peak frequency in the signal spectrum and the spatial scale size setting. In Phase I the new device will be demonstrated and characterized; alternative techniques, such as imaging methods, will be assessed for possible combination with this method; and an optimized instrument will be designed for fabrication and delivery to FHWA during Phase II