LAUSR

Abstract The continuous progress in GNSS (Global Navigation Satellite System) has led to considering this measurement technique as a powerful tool for the detection of the displacement response on seismic events and a source of comprehensive information on seismic wave propagation. Hence, as a natural consequence of the significant performance of high-rate GNSS measurements, a lot of effort has been made to develop dedicated algorithms for the GNSS-seismology. At present, the relative positioning mode is considered as the most accurate method for coordinate displacement determination with GNSS measurements. This holds true providing that all errors are carefully modelled or significantly reduced, which is not a trivial task in a wide area scenario. In this paper we validate the algorithms and the system developed for an automatic Galileo and GPS (Global Positioning System) high-rate signals processing over medium-length baselines. The system aims at the characterisation of the displacement response to seismic events, which are induced by mining exploitation. Addressing the requirements of the monitoring network, the system takes advantage of a ionosphere-weighted positioning model and a multi-baseline solution, which may be considered as superior with respect to the commonly employed single-baseline mode. The validation of the system feasibility was performed in two manners: by processing the data collected during actual MW 3.8 seismic event and with the use of single-axis shake table. The results of the former experiment showed a high agreement between the GNSS and accelerometer-derived results in a frequency domain. The latter proved that the system is capable of detecting the dynamic displacements with a millimetre-level precision at distances of over 30 km from the reference stations.