Multi-dimensional Imaging

Chapter 17Passive Polarimetric Imaging

Daniel A. LeMaster and Michael T. Eismann

Air Force Research Laboratory, USA

17.1 Introduction

The polarization properties of emitted, reflected, and scattered light are useful tools in remote sensing. These properties are inferred from a collection of radiometric measurements made by a device called a polarimeter. An imaging polarimeter extends this collection of measurements over a two-dimensional array of samples.

Imaging polarimetry has applications extending from medical diagnostics to astronomy. This chapter is devoted to the specific topic of passive broadband electro-optical and infrared Stokes imaging polarimetry for surveillance and reconnaissance in natural environments. Within this scope, there are numerous applications including clutter suppression and contrast enhancement [[1–6]], image segmentation [7], material characterization [[8–10]], shape extraction [11], and imaging through scattering media [[12, 13]]. Additional applications exists and, even among the applications specified, this list is reductive.

Though much of the material presented here is independent of any particular sensor, the scope of this chapter is limited in its discussion of architectures for polarization imagers. Sections 17.5 and 17.6 concentrate on modulated polarimeter technology. For instance, rotating analyzer and microgrid polarimeters are considered from both a data reduction matrix point of view and as linear systems using Fourier analysis. ...