Uncertainty calculations involving spatial correlation in coordinate metrology

For much of the 20th century, metrological traceability in industrial applications was achieved through the use of gauge blocks and similar hard gauges. With the introduction of new measurement modalities such as the coordinate measuring machine (CMM), laser interferometry, and atomic force microscopy (AFM), the route to traceability in manufacturing engineering is less direct and uncertainty evaluation is more challenging. This paper discusses uncertainty evaluation approaches based on Gaussian process models that enable key uncertainty calculations to be evaluated using relatively simple formulæ.