<title>Measurements of midwave and longwave infrared polarization from water</title>

Abstract

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 show and interpret measurements in midwave (-4-5 rim) and longwave (-10-1 1.5 jtm) 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 regions of sunglmt, 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.

Blue sun reflected from water: optical lessons from observations of nature

“…Glints are partially polarized by reflection and become 100% polarized when the reflection angle is very near the Brewster angle (approximately 53°). [12][13][14] This is indicated in the plots of Fig. 7 that show the s-and p-polarized reflectivity on the left and the corresponding degree of polarization 15 on the right for red light reflected from water.…”