Global Navigation Satellite Systems (GNSS) technology has been a consistent alternative to monitor and detect structural deformation using geodetic receivers. The role of low cost GNSS receivers have been explored in recent years and this study proposes the use of two such receivers as master and rover respectively to detect fast deformations. Single differenced observations of C/A code and L1 GPS carrier phase are differenced in time to obtain positions and velocities of a rover receiver and the performance of these observations in deformation detection is seen. Additional constraints of baseline between the master and rover are shown to improve the performance with successful detection of de?ections through rover velocity readings. Continuing previous research, another door for the use of low cost receivers to reliably detect deformations is opened and the real time use of such methodology can be explored
