Research

We are a research group which focuses on ground surface deformation monitoring and its data processing. 

(1)Deformation Monitoring System integrated Multi-Sensor (GPS, clinometer, total station electronic tacheometer)

We developed a GNSS deformation monitoring systerm which combined single antenna GPS system and multi-antenna systerm. The developed monitoring systerm greatly reduces hardware costs of GNSS deformation monitoring systerm. This systerm has advantages of all weather operations, high degree of automation, high-precision and dispensing with intervisible measuring stations, so it is suitable for landslide, dam, industrial factory building, etc slowly continuous automatic deformation monitoring.

Reference

Chan W S, Xu Y L, Ding X L, Dai W J. An integrated GPS–accelerometer data processing technique for structural deformation monitoring[J]. Journal of Geodesy, 2006, 80(12):705-719.

(2)GNSS deformation monitoring theory and method

We developed some model, e.g. GNSS observations stochastic model, regional precision tropospheric delay correction model, multipath error feature and delay correction model, to improve GNSS monitoring precision. We also use some deformation analysis methods, e.g. Kalman filter, EMD, wavelet, ICA, to extract some useful imformation in GNSS deformation series。

Reference

Bin Liu, Wujiao Dai *, Ning Liu. Extracting seasonal deformations of the Nepal Himalaya region from vertical GPS position time series using Independent Component Analysis [J]. Advance Space Research (2017)

Wujiao Dai*, Dawei Huang, Changsheng Cai. Multipath mitigation via component analysis methods for GPS dynamic deformation monitoring [J]. GPS Solutions, 2014(18):417-428.

Dai W J, Ding X L, Zhu J J, et al.EMD Filter Method and Its Application in GPS Multipath[J]. Acta Geodaetica et Cartographica Sinica,2006, 35(11): 321-327.

(3)Spatio-temporal deformation data analysis theory and method

We focus on take spatial correlation and temporal correlation into consideration. And we bring spatio-temporal Kalman filter, spatio-temporal ICA into deformation data analysis. 

Reference

Wujiao Dai*, Ning Liu, Rock Santerre and Jiabao Pan. Dam Deformation Monitoring Data Analysis Using Space-Time Kalman Filter [J]. ISPRS International Journal of Geo-Information. 2016, 5, 236. 

Dawei Huang, Wujiao Dai and Feixue Luo. ICA Spatiotemporal Filtering Method and Its Application in GPS Deformation Monitoring [J]. Applied Mechanics and Materials Vols. 204-208 (2012) pp 2806-2812