title: The copula: a tool for simulating speckle dynamics.
abstract: Use of a copula for generating a sequence of correlated speckle patterns is introduced. The chief characteristic of this algorithm is that it generates a continuous speckle sequence with a specified evolution of the correlation and does so with just two arrays of random numbers. Thus, physically realistic temporally varying speckle patterns with proper first- and second-order statistics are easily realized. We illustrate use of the algorithm for generating sequences with prescribed Gaussian, exponential, and equal-interval correlations and demonstrate how correlation times can be specified independently. This approach to generating sequences of random realizations with prescribed correlations should prove useful in modeling such phenomena as dynamic light scatter, flow-dependent laser speckle contrast, and propagation of spatial coherence.
authors.affiliation: Department of Biomedical Engineering, Oregon Health and Science University, 3303 SW Bond Avenue, Portland, Oregon 97239, USA. donald.duncan@bme.ogi.edu
authors.forename: Donald D
authors.initials: DD
authors.lastname: Duncan
authors.forename: Sean J
authors.initials: SJ
authors.lastname: Kirkpatrick
mesh_terms: D000465:Algorithms; D003198:Computer Simulation; D007090:Image Interpretation, Computer-Assisted; D007834:Lasers; D008027:Light