  The propagation of coherent light through a random scattering medium
generates speckle pattern. Although the speckle is random in nature, the object
information is scrambled into it. The scrambled object information can be
retrieved using off-axis holographic technique where the retrieval is made from
coherence hologram which is constructed from the interferogram formed by object
speckle and a tilted reference speckle. It is shown that the SNR of the object
retrieved from the coherence hologram, calculated from the far-field intensity
correlation of the interferogram, depends on the average number of reference
speckles. The effect of average number of reference speckles on the SNR of the
retrieved object in off-axis holographic technique is investigated
experimentally by changing the reference speckle while keeping the object
speckle unchanged. The experimental observations are presented in this paper.
