DOP, DD, PD as a function of depth and depolarization: (a) isotropic depolarization; (b) anisotropic depolarization; (c), (d) aniso. dep. with diattenuation; (e), (f) aniso. dep. with retardation; (g), (h) aniso. dep. with retardation but no circular birefringence; (i), (j) aniso. dep. with diattenuation and retardation.