Fig. 1: Light is transmitted through or reflected from different samples.

a An absorptive sample with a nonuniform transmittance distribution. b A reflective sample with a nonuniform reflectance distribution. c A transparent (weakly-absorbing) sample with a nonuniform RI or thickness distribution. d A sample with a uniform transmittance distribution. e A sample with a uniform transmittance distribution placed before atmospheric turbulence with inhomogeneous RI distribution. f A reflective sample with a nonuniform surface height distribution