Seeing seagrasses sidewards: marine angiosperms and the Stokes' polarization parameters

Abstract

Mapping of marine benthic flora using remote sensing techniques has been used to assess the dynamics of environmental conditions in coastal areas. Mostly studies used panchromatic/colour aerial photography and/or medium resolution multispectral satellite imagery to create time series showing the change of seagrass distribution, as indicator species of environmental conditions. While successful within their project parameters, these studies were limited by conditions at time of image capture, such as sun-glare, turbidity, wave action and low contrast in deeper waters due to absorption and scattering. The use of polarized multispectral imagery has the potential to overcome, or at least reduce these problems such that a finer detail of benthic flora may become visible. This paper explores the theoretical background in the application of polarization for mapping seagrass and other marine benthic flora. It also discusses a possible operational design using a low cost airborne multispectral camera.