The partially-coherent theorem, the Karhunen-Loe′ve expansion of generalized prolate-spheroidal function and coherent imaging theorem are used to analyse the propagation characterization of turbulent average mutual intensity of weak atmospheric turbulence illuminating system and imaging of mirror objects placed in turbulent medium. It is demonstrated that double passage imaging leads to an improvement in image quality (surperresolution) only for the reflective beam whose coherent scale is smaller than the scale of the aperture of imaging system.