Wireless sensor network for Ground Instability Monitoring (Wi-GIM) project aims, in the frame of EU LIFE+ program, to develop an accurate, flexible and low-cost system for ground deformation monitoring. The Wi-GIM system is based on two types of wireless devices: the nodes (sensor node - SN) and base stations (Base Station - BS). The movement of ground is detected by acquiring the position of each of the SN that are organized in a wireless sensor network (WSN), whose position is determined by integrating two different technologies, specifically designed for the purpose. The data collected by technology 1 are processed with the data collected by technology 2 in order increase the accuracy of the system. The displacements of the landslide can be then displayed in different modes, including 3D.