Conservative Polarimetric Scatterers and Their Role in Incorrect Extensions of the Cameron Decomposition

A unified three-component scattering model for polarimetric coherent target decomposition

“…As stated by Cameron (Cameron and Rais 2006), the unambiguous range of variation for the orientation angle ψ of the symmetric scatterer is the interval (−π 2, π 2), but the diagonalization angle ψ ± nπ/4, n ∈ {1, 3} of the third component in equation (29) still has two solutions between the interval. In this article, we determine the diagonalization angle in the right-left (R, L) circular basis equation (30) as the determination of the right-or left-sense helix in SDH decomposition (Krogager and Czyz 1995):…”

“…a quarter wave device has a scatterer type z = ±i). In 2006, Cameron mapped the symmetric scatterer unit disc to the closed symmetric scatterer unit sphere to represent the symmetric scatterer space with two complicated angle parameters θ s (x, y) and ϕ s (x, y) (Cameron and Rais 2006), where (x, y) represent the coordinates of the corresponding symmetric scattering type z in the unit disc (figure 1). In this part, we will propose another strategy to map the symmetric scatterer unit disc to the symmetric scatterer unit sphere with two simpler parameters of concise physical meanings.…”

“…As the conjugate pairs along the rim of the unit disc in figure 1 represent the same scatterer (Cameron and Rais 2006), the only difference is that the scatterer orientation angle is 0 for one point and π/2 for the other. Therefore, a more natural representation of symmetric scatterer space would be a closed surface formed by joining the unit disc at conjugate pairs along the rim of the disc.…”

“…In 2006, Cameron simplified the distance metric equation (12) as a more intuitive form, while the equivalent form is still very complicated (Cameron and Rais 2006):…”

“…Based on the two basic physical properties of radar scatterers -reciprocity and symmetry - Cameron et al (1996) proposed an approach to decompose an arbitrary polarization scattering matrix into three orthogonal components, namely, (1) the nonreciprocal scattering component; (2) the maximum symmetric scattering component; and (3) the minimum symmetric scattering component Leung 1990, Cameron andRais 2006). In 2002, Touzi and Charbonneau (2002) expressed the maximum symmetric scattering component on the basis of the trihedral-dihedral scatterer, and both the direction of the vector and the channel phase difference are considered as potential sources of target information.…”