Underwater hologrammetry: aberrations in the real image of an underwater object when replayed in air

The use of holography in the optical inspection and measurement of three-dimensional objects, now known as hologrammetry, places considerable emphasis on geometric precision and high resolution in the reconstructed real image. A discussion of the factors which dictate image fidelity in reconstruction must include an assessment of potential sources of optical aberration. In this paper the authors consider the aberrations introduced when the refractive index of the medium in which the subject is located differs from that in which the real image is replayed, addressing specifically their quantitative evaluation in relation to underwater hologrammetry.