An improved mixed total least squares method for strain inversion from distance changes

Based on the deficiency of the traditional total least squares method (TLS) in the field of geodetic inversion, the mixed error characteristics of the errors in variables (EIV) model were analyzed by considering the distance azimuth measurement error in strain inversion from distance changes, which resulted in the improved mixed total least squares method (IMTLS) with generalized mixed EIV model. Finally, three comparison schemes of strain inversion from distance changes using measured data were implemented to test the proposed method. The results showed that the IMTLS method outperformed the traditional least squares (LS) and TLS methods in parameters estimation, accuracy evaluation, actual EIV model characteristics, and five strain eigenvalues.