Principles of Modern Radar - Volume 2 1891121537

592 CHAPTER 13 Introduction to Radar Polarimetry• Scattering matrix definition for radar targets, Sinclair and Jones formulations, transformationof the matrix by change of bases between orthogonal polarization states• Eigendecomposition of the scattering matrix using unitary transformations• Determination of optimal transmit/receive polarization states that maximize or minimizebackscattered power• Null polarization states and Huynen polarization fork• Stokes reflection or Mueller matrix for partial polarization and its relationship withKennaugh matrix• Instrumentation setup for scattering matrix measurement (block diagram description)• Impact of polarimetry on radar target detection• Extraction of radar target features from polarimetric signature data• Polarimetric behavior of rain, sea, and ground clutter13.1.3 List of SymbolsThe following lists the variable names found within this chapter:r,θ,φ = radius, elevation and azimuth angles in the spherical coordinate systemf = frequency (Hz)ω = 2π f = radian frequency (rad/s)k = wavenumber (1/m)λ = wavelength (m)c = velocity of light (m/s)t = time (s)E = electric field intensity (V/m)δ = phase difference between orthogonal field components (rad)P = polarization ratiop = polarization efficiencye t = transmitter antenna polarizatione r = receive antenna polarizationê t ,ê r : transmit and receive polarization state (unit) vectorsCO-POL: Co-polarized transmit and receive statesCROSS-POL: Cross-polarized transmit and receive statesHuynen Fork Parameters:m = maximum received signal for the optimal tranmit polarization stateψ = orientation angle or tilt angle (radar coordinate system)γ = target polarizability angleν = target skip angle (characterizes multiple bounces)τ = ellipticity angle of the polarization ellipseAR = axial ratio of the polarization ellipse(g 0 ,g 1 ,g 2 ,g 3 ) = Stokes parametersg(a) = (g 0 ,g 1 ,g 2 ,g 3 ) = (g 0 ,g) = Stokes vector of transmit antenna with polarization ah(b) = (h 0 ,h 1 ,h 2 ,h 3 ) = (h 0 ,h) = Stokes vector of receive antenna with polarization bd = degree of polarizationM: Mueller matrixK: Kennaugh matrix