A system for determining the position, orientation and deformation in 3 dimensional space of a moving object in real-time is provided having a plurality of activatable markers which are mounted onto the object and a sensor section comprising a plurality of individual sensors as shown diagrammatically in FIG. 1. Individual markers are activated in sequence with only one marker energized at any time. Energy emitted by each activated marker is detected by the plurality of sensors positioned remotely. Since only one marker is activated at any time individual determination of the position of the particular energized marker is simplified. Individual sensors are arranged such that each sensor receives a different energy level from an energized marker depending on the relative position of the marker to the sensor. A control unit analyzes the energy distribution range to determine the actual marker position. The system compensates for ambient energy and sensor saturation.