Chi-Square Test


The Chi-square test is a global statistical test that checks the quality of the calculation model. For example, it indicates whether the residuals correspond to the a priori standard deviation. The Chi-square test result should not be < 20%. A value of 0% indicates, that the standard deviations do not represent the actual measurement precision.


A successful CHI-square test is most important for the calculation of base points. However, you can modify the threshold for the Chi-square test. For example, when you calculate detail points. See Calculation Project Settings.

Click the Show Measurement link to open the Measurement dialog box. In the Measurement dialog box, select the station or session, In the Measurement Data tab, check the standard deviation values.

By default, the a priori values are specified in the instrument settings. However you can update these values separately for each calculation project. Click the Update A Priori Standard Deviation link to adjust the values. Then, start the adjustment calculation again.