Three-dimensional position and velocity information can be extracted by direct analysis of the diffraction patterns of seeding particles in imaging velocimetry with real-time CCD cameras. The generalized Lorenz-Mie theory is shown to yield quantitatively accurate models of particle position, such that it can be deduced from typical experimental particle images with an accuracy of the order of 20 microm and an error of 11 gray levels rms, data obtained by comparison of theoretical and experimental images. Both the theory and an experimental verification of the problem presented here are discussed.

This paper describes the experimental imaging of a spherical particle diffraction pattern obtained in back, forward and side scattering configurations, using illumination from three different beam shapes. The experimental problems encountered for each of the viewing configurations and the theoretical analysis of the diffraction pattern of the particle on its image plane using the generalized Lorenz-Mie theory are discussed. The images obtained are quantitatively compared with calculated results and implications for particle position estimation are discussed.

This paper describes the imaging of spherical and non-spherical particle diffraction patterns using plane-wave illumination. A discussion is presented on both the theoretical analysis of the diffraction pattern of the particle on its image plane using the Lorenz–Mie theory and its applicability to non-spherical particles. The images obtained for both spherical and non-spherical particles are quantitatively compared to calculated results, and implications for particle position estimation of non-spherical particles are discussed.

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Three-dimensional twin-pulsed digital holography is used to separate the x, y and z displacement components in a rotating disc. The technique is able to distinguish the rotation and displacement movement along the x y plane from the out-of-plane z displacement. The results show that three-dimensional twin-pulsed digital holography may be used to derotate the object by combining information from three different illumination positions.