Derivation of a Signed Cameron Decomposition Asymmetry Parameter and Relationship of Cameron to Huynen Decomposition Parameters

An alternate definition of the asymmetry parameter τ, appearing in the Cameron decomposition is presented. The new definition is signed as τ_s, but in absolute value, it is equivalent to the previous definition. The Cameron decomposition signed asymmetry parameter τ_s is given in terms of the Huynen decomposition parameters, including but not limited to the Huynen helicity (asymmetry) parameter. It is demonstrated that the Huynen decomposition asymmetry parameter is a poor indicator of scatterer symmetry. The relationship between the Cameron and Huynen decomposition parameters is examined for special cases.