Acta Geodaetica et Cartographica Sinica ›› 2022, Vol. 51 ›› Issue (3): 340-350.doi: 10.11947/j.AGCS.2022.20200597

• Geodesy and Navigation • Previous Articles     Next Articles

A separable nonlinear least squares solution method based on Moore-Penrose generalized inverse and solid matrix

WANG Ke1,2, LIU Guolin2, FU Zhengqing2, WANG Luyao2   

  1. 1. School of Civil and Architectural Engineering, Shandong University of Technology, Zibo 255000, China;
    2. College of Geodesy and Geomatics, Shandong University of Science and Technology, Qingdao 266590, China
  • Received:2020-12-16 Revised:2021-10-11 Published:2022-03-30
  • Supported by:
    The National Natural Science Foundation of China (No. 42074009); The Natural Science Foundation of Shandong Province of China (No. ZR2020MD043)

Abstract: A separable nonlinear least squares algorithm based on Moore-Penrose generalized inverse and solid matrix is proposed to solve the special structure of linear combination of nonlinear functions in the field of surveying and mapping. Firstly, the variable projection algorithm is used to eliminate the linear parameters in the separable nonlinear model, and the original nonlinear optimization problem with two kinds of parameters is transformed into the least squares problem with only nonlinear parameters. Then, the first-order partial derivative of the least squares objective function is calculated based on the theory of differentiation of Moore-Penrose inverse matrix and solid matrix. Then the LM method of nonlinear optimization is used to solve the optimal estimation of nonlinear parameters. Finally, the optimal solution of linear parameters is obtained by linear least square method. The exponential model fitting experiment and airborne LiDAR full-waveform parameter solving experiment are used to compare the proposed method with the traditional optimization method without separation of parameters. The results show that the separable nonlinear least squares solution method based on the Moore-Penrose generalized inverse and the solid matrix is less dependent on the initial value of the parameter, avoids the ill-conditioned problem caused by the linear parameter in the iterative process, and the algorithm is robust. It provides a new idea for solving the separable nonlinear least squares problem in the field of surveying and mapping, and also expands the application of separable nonlinear least squares method.

Key words: separable nonlinear least squares method, nonlinear model, parameter estimation, variable projection algorithm

CLC Number: