1. A metrology system for measuring parameters of a structure, the system comprising: an optical system configured for detecting light reflection of incident radiation from the structure and generating measured data indicative of angular phase of the detected light components corresponding to reflections of illuminating light components having different angles of incidence, and a control unit configured for receiving and processing the measured data and generating a corresponding phase map indicative of the phase variation along at least two dimensions, and analyzing the phase map using modeled data for determining one or more parameters of the structure.