A system (100) and corresponding method are presented. the system comprises: an illumination unit (120) comprising at least one light source (122) configured for emitting coherent illumination of one or more selected wavelength ranges having selected illumination modulation pattern and for directing said illumination onto one or more selected inspection regions； and a collection unit (140) comprising at least one detector array (142) and imaging optical arrangement (144) configured for collecting interacting light from the one or more selected inspection regions and for generating corresponding one or more sequences of image data pieces at selected sampling rate. The image data pieces being indicative of secondary speckle patterns formed in collected interacting light. The illumination modulation pattern is selected for increasing temporal bandwidth collection of speckle patterns associated with temporal shifts in said one or more inspection regions.
