Geodetic techniques play a key role in the prediction and mitigation of risk posed by volcanic eruptions and volcanic collapses. However, our capacity to forecast these dramatic events remains elusive and strategies from geodetic techniques are required to enhance results. In this dissertation, I develop a new strategy that conceptualizes the design of a geodetic network using the strengths of each geodetic technique and integrate them within a 3D deformation surface. I apply this methodology to Arenal volcano in Costa Rica and Tungurahua volcano in Ecuador. In 2010, Arenal ended a four-decade long episode of growth that emplaced about half a cubic kilometre on its western flank. I develop and survey a geodetic network that integrates GPS, tacheometry and INSAR within the same reference frame. Based on the resulting 3D deformation field rate, I assess the effect of the post -1968 erupted material on the 3D Finite Element Model (FEM). The results suggest that the Arenal edifice is sagging in its basal layers and that the eastern flank may be cause for concern regarding its stability. Tungurahua is a restless volcano that has shown effusive phases of different intensity since it re-activation in 1999. I integrated the GPS rate and the Persistent Scatter InSAR rate. Based on the integrated deformation surface, I use simple analytical models and discover that half of the magma intruded in the crust during the period of study has contributed to the volcano's endogenous growth. I use a Kalman filter that enhances the GPS time series signal and discover a 3 to 4 month precursor signal as well as a change of the magma pathways. In both volcanoes, the developed methodology enhances geodetic data and provides a greater insight into volcanic processes.