Patent ID: 8040528
Filing Date: 2011-10-18
Classification: E02F,G01B,G01C

Abstract:
1. A method for determining rotational position of a target in a target tracking system, said target comprising a plurality of light emitting elements arranged circumferentially around the target, and said target tracking system further comprising a tracker unit capable of detecting light emitted by said light emitting elements, the method comprising: emitting from a plurality of said light emitting elements an omnidirectional synchronization signal; detecting in the tracker unit said synchronization signal; activating said light emitting elements sequentially starting from a reference direction, wherein each light emitting element is activated for a predetermined time and emits light during the time it is activated; detecting in the tracker unit a time when a maximum amount of light is received from the target; and calculating the reference direction for the target relative to a coordinate system based on the time interval between detection of the synchronization signal and the detection of a maximum amount of light received from the target.