As the need for accurate and non-invasive optical characterization and diagnostic techniques is rapidly increasing, it is imperative to find improved ways of extracting the additional information contained within the measured parameters of the scattered light. This is the first specialized monograph on photopolarimetry, a rapidly developing, multidisciplinary topic with numerous military, ecological remote-sensing, astrophysical, biomedical, and technological applications. The main objective is to describe and discuss techniques developed in various disciplines to acquire useful information from the polarization signal of scattered electromagnetic waves. It focuses on the state-of-the-art in polarimetric detection, characterization, and remote sensing, including military and environmental monitoring as well as terrestrial, atmospheric, and biomedical characterization. The book identifies polarimetric techniques that have been especially successful for various applications as well as the future needs of the various research communities. The monograph is intended to facilitate cross-pollination of ideas and thereby improve research efficiency and help advance the field of polarimetry into the future. The book is thoroughly interdisciplinary and contains only invited review chapters written by leading experts in the respective fields. It will be useful to science professionals, engineers, and graduate students working in a broad range of disciplines: optics, electromagnetics, atmospheric radiation and remote sensing, radar meteorology, oceanography, climate research, astrophysics, optical engineering and technology, particle characterization, and biomedical optics.