NASA Kennedy Space Center developed the Inductive Non-Contact Position Sensor for motion control applications. The sensor was designed to monitor the precise movements of an optical inspection system that measured defects in Space Shuttle windows.
The technology is precise, small, inexpensive, and provides absolute position. It can measure accuracy of position down to 400 nanometers over a total range of 200 microns. A highly linear output makes computation easy by using a low-cost microcontroller. The high signal-to-noise ratio allows the sensor to operate in noisy environments.