Introduction to Radar Polarimetry
Abstract
When an electromagnetic wave is scattered by an object its polarization generally changes. The change depends on the kind of object. It is therefore useful to study these changes and relate them to object features. This is the objective of polarimetry. The subject serves as an introduction to polarimetry with microwaves, i.e., radar polarimetry. The subject deserves attention nowadays because of the growing number of polarimetric radars. These radars are able to measure the polarization changes caused by scattering at the earth surface. The first chapters contains some basic electromagnetic theory relevant to the remainder of the report. The definition of polarization is the subject of the next chapter. Polarization is a two parameter quantity for which several representations exist. Some are given, together with a few methods to generate a wave with an arbitrary polarization. The polarization of a wave can be changed by several different physical mechanisms. These are discussed in chapter 4. The scattering matrix describes the way in which the polarization of a wave is altered by scattering. Some properties and examples are given. The problem of minimization and maximization of the power received by a radar illuminating an object with a given scattering matrix is solved. The scattering matrix describes the scattering by a single stationary target; it cannot be used to describe the scattering by a time-varying or distributed target. The Stokes matrix should be used instead. The last chapter is devoted to the definition and some properties of this matrix.
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 23, 1991
- Accession Number
- ADA236338
Entities
People
- J. S. Groot
Organizations
- Netherlands Organisation for Applied Scientific Research