Strategies and Methods for Multi-Epoch Deformation Analysis based on Geodetic Networks

There is a long-lasting discussion within geodesy, which methods and strategies are adequate for a rigorous mathematical-statistical analysis of geodetic networks, when measuring results are available for several epochs. In this paper, first general prerequisites and typical problems are outlined, which define the framework for the here presented new concepts. Then the basic ideas for data-driven and model-driven analyses techniques are described, leading to the conclusion that normally a data-driven technique is restricted to (multiple) congruency tests, whereas all further analysis concepts have to be based on some prior information or physical model describing the behaviour of objects. Different computational methods are discussed in detail, like the consecutive two-epoch analysis, the multiple-epoch-congruency test and the newly developed hypothesis constrained multiple-epoch analysis. At the end a practical example for congruency analysis of multiple observed levelling networks is given.