The accuracy of Young’s fringe method for reducing velocity field data is compromised by a spatially incoherent background field which originates in the random locations of the seeding particles. The probability density function for the spatial frequency cutoff of this background is derived as a function of the particle count, the distribution governing the power in each frequency interval is derived, and conditions are found under which the Van Cittert-Zernike theorem applies. The background field resembles the far field of a partially coherent source in the high particle count limit, but departs significantly at low and moderate counts.
© 1990 Optical Society of America
Original Manuscript: March 1, 1989
Published: December 10, 1990
Robert Rubinstein and Paul S. Greenberg, "Particle image fields and partial coherence," Appl. Opt. 29, 5282-5291 (1990)