The Wave Nature of EM Energy and an Introduction of the Polarization Ellipse

doi:10.1117/3.817304.ch3

Book: Fundamentals of Polarimetric Remote Sensing

Author(s): John R. Schott

Published: 2009

https://doi.org/10.1117/3.817304.ch3

Author Affiliations +

Abstract

This chapter continues our review of basic physics by reminding the reader of ways to describe the wave nature of EM energy and introducing ways to describe the polarimetric properties of a beam of energy. These topics are covered in greater detail in Collett (1993) and Goldstein (2003). 3.1 Wave Nature of EM Energy The polarimetric properties of light are most easily introduced using the wave nature of EM energy. So we begin with a brief review from freshman physics applicable to fully polarized radiation. Recall that the electric field associated with a beam of EM energy traveling in the z direction can be described in terms of the vector sum of the electric fields of two transverse component waves oscillating at right angles to each other and to the direction of propagation. The field strength at any location (z) and time (t) can be expressed as Îµ x =Îµ 0x sin(Ïtâkz)=Îµ 0x sin(Ïtâ2Ïz Î» ) Îµ y =Îµ 0y sin(Ïtâkz)=Îµ 0y sin(Ïtâ2Ïz Î» ), where Îµ x and Îµ y are the instantaneous amplitudes of the x and y components, Îµ 0x and Îµ 0y are the maximum amplitudes, t is time, Ï=2Ïv is the angular frequency, v is the frequency [cycles/sec], k=Ïâc , c is the velocity of the wave in the medium, z is the location along the direction of the propagation, and Î» is the wavelength.