Abstract: A position detection system is able to detect the three dimensional position of at least one target (10). Each target (10) is configured to act as a retro-reflector for light incident from any direction. At least one light emitter illuminates the at least one target (10) and at least one detector (24) is provided for detecting and taking measurements of light retro-reflected from a target (10). There is also provided a processor for processing measurements taken by each detector (24) to determine the three dimensional position of the at least one target (10).

Abstract: A measurement device (120) includes a light director and a spatial light modulator (130). The light director is disposed to direct light to the spatial light modulator (130) and the spatial light modulator (130) is disposed to receive light from the light director and to modulate it to form an intensity pattern. An optical element is disposed to receive light which formed the intensity pattern and is arranged to magnify the intensity pattern into a measurement space. A detector (142) is disposed to detect light reflected from the measurement space.