The correlation effect of waves scattered from random media has attracted c
onsiderable interest in recent years. In particular, the angular correlatio
n function (ACF) of waves scattered from rough surfaces and volumes has bee
n studied extensively, and the characteristics of the angular memory effect
(AME), which was first described by Feng et al. [1988], were reported for
different surface conditions. Applications of AME, including height profili
ng in interferometric synthetic aperture radar (INSAR) and detection of bur
ied objects, have been proposed and studied by researchers using numerical
and experimental techniques. However, most of the recent studies of AME hav
e been confined to the area of waves scattered from rough surfaces. In this
paper we will investigate the angular memory signature of volume scatterer
s. Numerical and experimental studies on the ACF of waves scattered from ra
ndomly distributed cylinders are presented at millimeter-wave frequencies (
80-105 GHz). It has been found that the angular width of ACF for volume sca
ttering is narrower and shorter than that for random rough surfaces.