Passive Polarimetric Imaging

Passive electro-optical polarimetric imaging is a form of remote sensing in which the properties associated with electromagnetic field orientation are exploited as a means to discriminate between objects in an extended scene. The purpose of this chapter is to introduce some fundamental concepts in the science of imaging polarimetry. These concepts include the Stokes-Mueller description of polarized light, the physical mechanisms that contribute to polarimetric image contrast, a mathematical description of several polarimetric imaging systems, and an example target detection algorithm. Polarimetric image contrast is discussed in terms of reflected, emitted, and scattered light. Special emphasis is placed upon atmospheric effects and, separately, material properties in terms of the polarimetric bidirectional reflectance distribution function. Division-of-time and division-of-focal-plane modulated imaging polarimeters are considered from both the data reduction matrix and Fourier analysis points-of-view. Procedures for the radiometric and polarimetric calibration of imaging systems are also provided.