applied-geodesy/jag3d: JAG3Dv20230804

The calibration of measuring equipment is essential in geodesy and metrology. In length measurement technology, for instance, it enables the traceability of measured values to the SI base unit of the meter. High demands are placed on the standards used to supply the reference values in order to ensure conformity with national and international standards and norms such as DIN or ISO. In Germany, the Physikalisch-Technische Bundesanstalt, PTB, as the national metrology institute and supreme technical authority for metrology, is responsible for this task.

Thanks to the work of organizations like the Gesellschaft zur Kalibrierung geodätischer Messmittel e.V. (GKGM), the calibration of measuring instruments has a certain self-image at least in geodesy. However, the traceability of adjustment algorithms in software packages used is often not taken into account. According to the ISO 10360-6, which deals with the estimation of errors in computing Gaussian associated features, the PTB offers a service to certify metrological adjustment algorithms called TraCIM - short for Traceability for Computational-Intensive Metrology.

JAG3D's module JUniForm has successfully passed the verification test of the implemented algorithms for computing Gaussian associated features. A total of 44 data sets were used to test the implemented algorithms for basic features such as straight line, plane, circle, cylinder, sphere and cone. The resulting maximum permissible errors (MPE) of the estimated parameters were always smaller than the specified threshold values 0.1 μm and 0.1 μrad.

Proper handling of measured values is complex and requires not only the consideration of calibrated measuring instruments but also the use of reliable adjustment algorithms for a holistic evaluation of the full measuring process. More details are given in the full TraCIM report.

• Damping value of implemented Levenberg-Marquardt algorithm is not overwritten/reset after fitting process

• Fixed displayed unit of points in default HTML template, cf. #14493