Grazing angle dependence of IR radiance of the Hudson river

We retrieve water currents in rivers and estuaries from remotely collected MWIR imagery by detecting a signal consisting of small-scale temperature variations and observing their advection by the local mean flow [1]. This thermal signature being measured is a function of a wide range of environmental variables, and a primary issue is to better understand these dependencies. An experiment was designed and conducted with both an airborne and a stationary camera that was mounted on the top of the Palisades, overlooking a site on the Hudson having slowly varying, smooth bathymetry and supporting instruments installed in and above the water. Imagery was collected over several weeks having a range of tidal flows and atmospheric conditions. This contribution provides a short overview of the experiment and focuses on model predictions for the sources of radiance at the two cameras.