@article{TuWangWalteretal.2014,
  author    = {Tu, Rui and Wang, Rongjiang and Walter, Thomas R. and Diao, FaQi},
  title     = {Adaptive recognition and correction of baseline shifts from collocated GPS and accelerometer using two phases Kalman filter},
  series = {Advances in space research},
  volume    = {54},
  journal   = {Advances in space research},
  number    = {9},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2014.07.008},
  pages     = {1924 -- 1932},
  year      = {2014},
  abstract  = {The real-time recognition and precise correction of baseline shifts in strong-motion records is a critical issue for GPS and accelerometer combined processing. This paper proposes a method to adaptively recognize and correct baseline shifts in strong-motion records by utilizing GPS measurements using two phases Kalman filter. By defining four kinds of learning statistics and criteria, the time series of estimated baseline shifts can be divided into four time intervals: initialization, static, transient and permanent. During the time interval in which the transient baseline shift is recognized, the dynamic noise of the Kalman filter system and the length of the baseline shifts estimation window are adaptively adjusted to yield a robust integration solution. The validations from an experimental and real datasets show that acceleration baseline shifts can be precisely recognized and corrected, thus, the combined system adaptively adjusted the estimation strategy to get a more robust solution. (C) 2014 COSPAR. Published by Elsevier Ltd. All rights reserved.},
  language  = {en}
}
@article{TuChen2014,
  author    = {Tu, Rui and Chen, Kejie},
  title     = {Tightly integrated processing of high-rate GPS and accelerometer observations by real-time estimation of transient baseline shifts},
  series = {The journal of navigation},
  volume    = {67},
  journal   = {The journal of navigation},
  number    = {5},
  publisher = {Cambridge Univ. Press},
  address   = {New York},
  issn      = {0373-4633},
  doi       = {10.1017/S0373463314000150},
  pages     = {869 -- 880},
  year      = {2014},
  abstract  = {The complementary advantages of high-rate Global Positioning System (GPS) and accelerometer observations for measuring seismic ground motion have been recognised in previous research. Here we propose an approach of tight integration of GPS and accelerometer measurements. The baseline shifts of the accelerometer are introduced as unknown parameters and estimated by a random walk process in the Precise Point Positioning (PPP) solution. To demonstrate the performance of the new strategy, we carried out several experiments using collocated GPS and accelerometer. The experimental results show that the baseline shifts of the accelerometer are automatically corrected, and high precision coseismic information of strong ground motion can be obtained in real-time. Additionally, the convergence and precision of the PPP is improved by the combined solution.},
  language  = {en}
}
@article{TuWang2014,
  author    = {Tu, Rui and Wang, Li},
  title     = {Real-time coseismic wave retrieving by integrated Kalman filter with observations of GPS, Glonass and strong-motion sensor},
  series = {Advances in space research},
  volume    = {53},
  journal   = {Advances in space research},
  number    = {1},
  publisher = {Elsevier},
  address   = {Oxford},
  issn      = {0273-1177},
  doi       = {10.1016/j.asr.2013.10.011},
  pages     = {130 -- 137},
  year      = {2014},
  abstract  = {A method of real-time coseismic wave retrieving was proposed based on the tight integration of GPS, Glonass and strong-motion sensor observations, the validation and precision analysis have been made by an experimental data. The series of results have been shown that: by the integrated Kalman filter and multi-sensors, the coseismic waves can be optimally recovered by complement the advantages of each other, especially when the observation conditions are very bad. In additional, the results are not significantly effected by different receiver clock error processes for the integration solution.},
  language  = {en}
}