Optical Tracking Markers | Retroreflective Materials
There are two types of optical tracking markers that can be used with PS-Tech’s optical tracking systems: passive and active markers.
Passive optical tracking markers consist of retro-reflective material, which reflects incoming IR light back into the light source. Such markers are available in different sizes as flat, round stickers, or in a spherical shape. Spherical markers have the advantage that they reflect light at each possible angle with respect to the tracking system, whereas flat markers only reflect light at an angle between 0 and 60 degrees to the tracking system.
Active optical tracking markers are infrared light emitting diodes (LEDs). Such markers require a wire or battery to operate and emit IR light directly. Because they do not rely on reflecting incoming IR light, such as retro-reflective makers, they can be used at a larger distance to the tracking system, thereby increasing the size of the measurement volume.
For most applications, passive markers are used. They provide the most flexible setup and allow users to quickly transform their own objects into tracked devices.