Acoustic Holography with Crossed Linear Arrays

This paper is an analysis of how acoustic (or microwave) holography can be applied to large masses, such as natural bodies of water or the earth, by means of a linear array of microphones and by scanning with one or more transmitters to produce holographic phase shifts. This type of hologram, in which the phased array has a conical antenna pattern, is shown to be superior to the area hologram for computing images in the near field. Computer simulations are given of virtual holograms and image reconstructions for specular and diffuse reflectors; simulations are also made for the case of pulse holography, which yields genuine three-dimensional images with reduced highlight distortions.