Dynamic concepts to handle geodetic networks with continuous monitoring data in areas with ground movements

Since decades the discrepancy exists that geodesists monitor changes of the earth surface resp. large engineering structures with most-modern equipment, but the results are computed and presented in a suboptimal manner: In many cases, the displacements are computed in relation to reference (datum) stations, which are not stable over a long time. Aside, the variations of an object are presented as coordinates for representative points with time stamps or with displacements rates (absolute values or velocities). Finally, nowadays often we have continuous measuring sensors and data, but there is no complete concept to treat variations continuously within the coordinate approach. In this paper at first the problems are outlined and open questions are formulated. Then some ideas are presented, how to analyse and describe coordinates in a continuous manner, taking into account the classical concepts and thinking of the surveying profession. The new ideas start with the definition of a stable reference frame over time, followed by the introduction of time dependent coordinates. A specific objective is to deliver day-by-day precise reference coordinate values for different groups, working on monitoring with their own sensors and computational concepts in the same area. These concepts are applied to an extended monitoring network of the mining authority Ruhrkohle AG (RAG), responsible for the eternal obligations that the German hard coal mining industry has left behind. This RUHR-network is located in the federal state North-Rhine-Westphalia within German, where after 300 years of coal mining larger and irregular ground movements can be expected.