Application of extended free net adjustment constraints in two-step analysis of deformation network

Two-step analysis of deformation network enables the extraction of geodynamical quantities from geodetic measurements campaigns in two steps. In the first step the measurements’ mathematical model is realized for each monitoring campaign and in the second step the deformation model is examined. The mathematical model is usually conceived as being absolutely correct, while the validity of the deformation model and its system noise is frequently limited. The deformation model is commonly presented by kinematic model although dynamic model might describes the geophysical reality more accurately. Dynamic model is usually characterized by nonlinearity, which makes difficult the analysis of deformations in relative to a stable datum. Therefore, many of the control networks that are used for deformation monitoring and are measured by geodetic measurements are currently defined by kinematic models. In monitoring networks, global effects can impair the data processing and the deformation analysis and cause the deviation of the network solution. Extended free net adjustment constraints is a mathematical method that effectively coping with global effects. An extended solution of geodetic network for deformation monitoring includes the solution of extended parameters, in addition to those received in a standard solution. Such a solution enables to sterilize the geodetic measurements from their datum definition content in the first step, and extract the deterministic movement in the second step. The paper shows the great potential of using combination of the extended free net adjustment constrains and the two-step analysis of deformation networks.