On a possibility for replacing calibration and self-calibration of optical measuring and surveying instruments

The author first analyses the role of calibration in the development of the industrial revolution in rationalising the measurement of physical quantities, and considers limitations of the concept of calibration. A promising alternative is in the development of technology providing direct relation of constituent measurements to fundamental physical units, as in determining length in terms of light path measured in wavelengths of light. The possibility is then discussed of using a similar approach for improving the performance of instruments being developed for use in close range surveying of three dimensional fields in engineering and medicine