ABSTRACT
This chapter discusses three final non-contact ranging techniques of potential interest: 1) interferometry, 2) range from focus, and 3) return signal intensity.
One of the most accurate and precise distance ranging methods known, interferometry has existed for many years in laboratory scenarios that afforded the necessary controlled or otherwise structured environment (Brown, 1985). Under such non-turbulent atmospheric conditions, laser interferometers can achieve fractional wavelength accuracy. Recent developments in optical technologies are making possible applications of this technique outside of laboratory scenarios.
