Abstract：In connection with the problem of EIV model’s coefficient matrix containing repetitive elements, The author improves the available weighted total least squares method through making the repeat element’s correction equal,taking into account the correlation between the elements of coefficient matrix, Then, the improved method is applied to the linear fitting, to solve the small rotation angle of 3D datum transformation model.The examples show that, compared with toprevious parameter estimation methods, the improved weighted total least squares (IWTLS ) method can obtation a more rational residual matrix of coefficient matrix.
