题 目：New approaches of GPS in deformation monitoring
时 间：2019年5月8日（周三） 上午10:00
地 点：卫星导航中心13楼会议室
报告人： Panos Psimoulis 英国诺丁汉大学地理空间研究所助理教授
主请人：耿江辉 教授
Abstract：The advances of GPS technology, such as the expansion of dense GPS networks with high sampling rate (even up to 10Hz), and the broader development of other satellite systems (GLONASS, BeiDou, etc.) have made GNSS an important tool in deformation monitoring of structures and geohazards. However, most of them are based on the analysis of the GPS coordinate time series aiming to determine the characteristics of the deformation and relate them to the current phenomenon. Two recent approaches have been developed to expand the potential use of GPS/GNSS in deformation monitoring applications. First approach is the analysis of the signal-to-noise ratio (SNR) of the GPS satellites signals to monitor short-period motion. This approach is based on the assumption that the multipath conditions for very short-period (~1min) remain practically stable, during which potential motion of the GPS antenna will have an impact on the multipath effect and its expression through the SNR satellite signals. Using simulated and real GPS data, it was proved that the SNR can be used to model dynamic motion of GPS antenna. Second approach is the analysis of GPS network data using temporal and spatial analysis algorithm for the detection anomalies potentially related to geohazards. The application of artificial neural networks and the spatial regression model are adopted to detect changes through the analysis of the time-history of the GPS records and their spatial correlation. Through their application in different case studies, it is shown that the temporal analysis is more effective for rapid, short-period changes, while the spatial analysis is more suitable for slowly developed anomalies.
Short Bio: Panos Psimoulis began his academic life as civil engineer, with a degree from University of Patras in 2004, where he continued for his post-graduate studies leading to an MSc and PhD in Civil Engineering in 2009, focusing on geodetic monitoring applications of stiff civil engineering structures. For the period 2010-2011, he was Teaching and Research Associate at the Athens University of Applied Sciences, which he left to continue his research as Research Fellow at the Geodesy and Geodynamics Lab in ETH Zurich, focusing on the application of high-rate GPS on seismology. Since 2013, he holds the position of Assistant Professor at the Nottingham Geospatial Institute of University of Nottingham. His research explores applications of deformation monitoring related to civil engineering structures and geohazards. Particular interests at the moment include GNSS time series analysis for bridge health monitoring, temporal and spatial analysis of GNSS networks for geohazards application and investigation of the potential of GNSS multipath for tracking changes.
