Radiation, Electromagnetic

Definition

Electromagnetic radiation is the means by which information is transmitted from an object to the sensor through an emitted, transmitted, or reflected electric and/or magnetic field. The interaction of the electromagnetic waves with the environment is strongly dependent on the wavelength and the geometrical, electrical, magnetic, and conductive properties of the interacting medium. Electromagnetic waves in different frequency bands tend to excite different interaction mechanisms such as electronic, molecular, or conductive. Electromagnetic radiation is the most commonly used means to retrieve information about an object by means of remote sensing techniques.

Introduction

Remote sensing is the methodology to remotely retrieve information about an object (Ulaby et al., 1981). This information is acquired by measuring changes that the object under investigation imposes on the interacting field. The latter can be an electromagnetic, acoustic, or gravitational field. The...