Ja. Pomarico et al., OPTICAL VELOCIMETRY BASED ON THE SPATIAL CORRELATION OF OFF-AXIS IMAGE SPECKLE PATTERNS, Optics communications, 133(1-6), 1997, pp. 27-32
A method is proposed for measuring the linear velocity of a moving rou
gh surface. It is based on maximizing the spatial correlation between
two laterally shifted image speckle patterns. Besides, an expression o
f a spatially variant point-spread function is given, which modifies t
he spatial distributions of the off-axis image speckle patterns.