A Correction Method for Sight Axis of Nonorthogonal Shafting Total Station after Calibration

The non-orthogonal shafting total station (N-total station) is designed for large-scale measurement field, and composed of two rotation axes and a sight axis. Each axis is defined by a direction vector and a fixed point. The dynamic pose of the sight axis is the key parameter to solve the space point coordinate. A correction method for the sight axis of the N-total station after calibration is proposed. There are six offset terms to be set as coefficients when the sight axis shifts. Based on the kinematic measurement model, a new sight axis can be reshaped with the solution of the coefficient obtained by the optimization method. The experimental results well verify that the calibration method is suitable for the N-total station.