Recovering coseismic point ground tilts from collocated high‐rate GPS and accelerometers

Abstract

[1] Rotational along with translational and strain measurements are essential for a complete description of the motion of a deformable body in a seismic event. We propose a new seismogeodetic approach where collocated high-rate GPS and accelerometer measurements are combined to estimate permanent and dynamic coseismic ground tilts at a point, whereas at present, only dynamic tilts are measured with either a dense seismic array or an expensive ring laser gyroscope. We estimate point tilts for a five-story structure on a shake table subjected to 13 earthquake strong motion records of increasing intensity. For the most intense record from the 2002 M7.9 Denali earthquake, we observe a peak-to-peak dynamic tilt of 0.12 ı and a permanent tilt of 0.16 ı for the structure's roof. Point tilts derived from networks of collocated GPS and accelerometers can be used to estimate the rotational component of the seismic wavefield for improved earthquake source characterization. Citation: Geng, J., D.Melgar, Y. Bock, E. Pantoli, and J. Restrepo (2013), Recovering coseismic point ground tilts from collocated high-rate

Predominant period and equivalent viscous damping ratio identification for a full‐scale building shake table test

“…While the first two methods described previously made use of the recorded total roof accelerations, this method utilizes the roof displacement response. The displacements were obtained at collocated locations by an optimal combination of observed accelerations and GPS displacements using a Kalman filter [38]. The resulting displacement has millimeter accuracy [39].…”

Cooperating the BDS, GPS, GLONASS and strong-motion observations for real-time deformation monitoring

“…Moreover, the baseline shift error is not only the product of translation and rotation of ground, but also the information of ground tilting during the motion period. By combining the collocated GNSS and SM records, we can both estimate the baseline shift, and recover the coseismic point ground tilting (Geng et al 2013b). Fig.…”

Adaptive recognition and correction of baseline shifts from collocated GPS and accelerometer using two phases Kalman filter

“…Moreover, the baseline shifts are mainly caused by the tilting and/or rotation of the ground, and have an important feature that it is zero or a constant value while there is no motion (Iwan et al, 1985;Graizer 2006;Wang et al, 2011;Geng et al, 2013b), so it is more sensitive to select the baseline shifts as learning statistics. Meanwhile, the high resolution acceleration signal can also be used to detect the state motions.…”

“…In Tu et al (2014) the baseline shifts are estimated firstly by Precise Point Positioning (PPP), then applied to the motions derived from acceleration to recover the coseismic waves. Moreover, while considering the baseline shifts are caused by the ground tilts (Graizer 2005(Graizer , 2006, the coseismic point ground tilts can be recovered from collocated high-rate GPS and accelerometers (Geng et al, 2013b). In cases where there are no baseline shifts or baseline shifts are robustly corrected, the high resolution acceleration records can be used to strengthen GPS for a better solution.…”