High-definition metrology
High-definition metrology refers to measurement of dimensional or other attributes of a surface or an object in which measurements are made densely across the observable extent of that surface or object, so that the measured attribute of the surface or object can be portrayed (displayed) with high-definition. In that sense the term high-definition metrology is analogous to high definition television. High-definition measurements are therefore contrasted with "global" or "overall" or "statistical" measurements which provide some single or coarsely sampled measurement values that do not define the surface or object attribute variations in detail. Whereas the latter measurements may provide an indication of some overall characteristic of the item being measured, high-definition metrology is used where it is desired to also know more precisely at what location certain attributes occur, or where their values are outside of some specified range of values. In precision manufacturing, for example, this knowledge may enable remedial action to be taken to correct or control process variables that affect the dimensions of a manufactured part or assembly.