Measuring three-dimensional surface displacements from combined InSAR and GPS data based on BFGS method

Jun Hu, Zhi Wei Li, Jian Jun Zhu, Xiaoli Ding, Chang Cheng Wang, Guang Cai Feng, Qian Sun

Research output: Journal article publicationJournal articleAcademic researchpeer-review

20 Citations (Scopus)

Abstract

InSAR has the advantages of wide spatial coverage, high spatial resolution and high precision, but it can only measure one-dimensional surface displacements in line-of-sight (LOS). While GPS can monitor three-dimensional surface displacements, it is generally with very low spatial resolution. In this paper, the method of combining InSAR and GPS to measure three-dimensional surface displacements with high spatial resolution is studied. Firstly, it is proved that a local optimization method is sufficient to achieve the global optimization solutions of the objective function model, which is used to optimize the InSAR and GPS integration. Then the BFGS method is introduced in this study to estimate the optimal value of the three-dimensional surface displacement velocities. Compared to the global optimization method or the analytical optimization method, the BFGS method is very simple in computing and easy to converge, and has good resistance to numerical instability. In the last of the paper, the results of numerical simulations and real data experiments over Southern California are presented. They show a great improvement of accuracy when the proposed methods are used. Especially, when the observation or interpolation errors lead to ill-condition in the coefficient matrix of normal equations, the analytical optimization method can result in great errors, while the BFGS method works very well.
Original languageChinese (Simplified)
Pages (from-to)117-126
Number of pages10
JournalActa Geophysica Sinica
Volume56
Issue number1
DOIs
Publication statusPublished - 1 Jan 2013

Keywords

  • 3D displacements monitoring
  • BFGS method
  • Convex function
  • GPS
  • InSAR

ASJC Scopus subject areas

  • Geophysics
  • Geochemistry and Petrology

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