G. Läufer

Monitoring of displacements with ground-based microwave interferometry: IBIS-S and IBIS-L

Abstract One fundamental component of early warning systems for natural hazards is displacement monitoring. Spaceborne SAR Interferometry has proven to be a powerful remote sensing tool for this task. Lately new ground-based SAR instruments are available. Their application field is wide and they combine high resolution and accuracy with the classical benefits of remote sensing techniques. Here, the principles of the microwave interferometer IBIS are presented, as well as its advantages and disadvantages compared to common monitoring techniques. IBIS can be operated in two modes: IBIS-S is a microwave interferometer capable of high frequency displacement monitoring of buildings and structures (up to 200 Hz); IBIS-L is a ground-based SAR for long-term displacement monitoring of buildings and natural phenomena as landslides, glaciers, etc. Exemplary three applications are presented: the use of IBIS-S for dynamic monitoring of a chimney; the use of IBIS-L for displacement monitoring in an active quarry and the long-term operation of IBIS-L as part of a “Volcano Fast Response System” (VFRS) on an active volcano.

Effect of stochastic model fitting on the significance of CORS coordinate time series parameters.

Abstract Based on the reprocessing of a regional continuously operating reference station (CORS) network the effect of stochastic modelling on the significance of coordinate time series parameters is investigated. The aim is to identify a suitable stochastic model for the time correlated time series. It is needed as stochastic model of the time series data and to enable a realistic statement about the significance of estimated parameters like velocity, offsets, annual signal. The approach of power-law noise stochastic modelling is applied and investigated. Estimated stochastic parameters and resulting models best fitting to the time series are shown and discussed. It is found that the stochastic parameters are strongly site specific. Utilizing such a best fitting stochastic model will yield realistic statements about accuracy and significance of parameters (velocity, offsets, annual signal). The application to the assessment of the velocity field of the network concludes the paper.