Assessment of simultaneous adjustment method for stability analysis of geodetic networks

Deformation survey using geodetic techniques for large buildings and landslides monitoring can be performed using multiple epoch’s method. The first step is the design of a reliable monitoring network. To compute the displacement, a coordinate system (datum) is to be established. Such a system is defined over a few points that are assumed to be stable during the campaign. We therefore require an efficient method for stable points’ detection. The simultaneous adjustment method is presented in the present contribution. L1 norm minimization method and global congruency test are the other two methods for this purpose. We aim to study the performance and sensitivity of simultaneous adjustment to identify the stable and unstable points using simulated data at four epochs. This method is then compared with the L1 norm method and the global congruency test for simulated and real data at two epochs. The results illustrates that increasing the observation epochs augments the ability of deformation analysis and stable points detection for simultaneous adjustment. In addition, simultaneous adjustment provides superior results over small displacements compared to the other two methods.