Measurement data fairing method

A measurement data fairing method that fits a geometrical element to measurement data and conducts fairing processing of the measurement data on the basis of a statistic of a residual of the measurement data with respect to the geometrical element, said method comprising:

• a fitting interval determination step for determining an interval in which the geometrical element is to be fitted to the measurement data;
• a geometrical element fitting step for extracting interval measurement data in the fitting interval from the measurement data and robustly fitting the geometrical element to the extracted interval measurement data;
• an outlier removal step for removing, on the basis of the result of the robust fitting conducted by the geometrical element fitting step, outlier from the interval measurement data and using the remaining interval measurement data as the interval measurement data;
• a statistic computation step for computing, with respect to the geometrical element fitted in the geometrical element fitting step, a statistic of a residual of the interval measurement data after the outlier removal step;
• and
• an invalid data removal step for removing, as invalid data, measurement data that exceeds a predetermined limit value of the statistic of the residual of the measurement data with respect to the geometrical element from the interval measurement data after the outlier removal step on the basis of the statistic of the residual computed in the statistic computation step, and using the remaining interval measurement data as the interval measurement data.