Measurements of midwave and longwave infrared polarization from water

In the largely unpolarized natural infrared environment, water stands out as a notably polarized source. Water surfaces appear partially polarized in the infrared through both reflection and emission. This polarization can be significant in environmental and military remote sensing applications where the water is either the intended source or possibly a false target, In this paper we shaw and interpret measurements in midwave (similar to 4-5 mu m) and longwave (similar to 10-11.5 mu m) infrared bands. The midwave images show up to 7% s polarization (horizontal) in regions where warm objects reflect from the water. The longwave data also show s polarization in legions of sunglint, but elsewhere exhibit p polarization (vertical). Where the background is clear sky, the longwave signal is p polarized by up to 5% at large incidence angles.