A method for pose determination from a pattern of four LEDs comprising the steps of; - Turning a current group of four LEDs on which is specially placed in a "T" shaped pattern, - Determining if all 4 LEDs in the current LED group are visible by a camera, - Identifying a center LED by calculating distances of all LEDs to other remaining three LEDs and selecting the LED which has the smallest total distance formed by summing up the distances to remaining three LEDs as the center LED, if all the LEDs in the current LED group are visible and - Determining that the center LED is ambiguous if the smallest total distance and the second smallest distance calculated are within predetermined percentage of each other, - Identifying a flank LED by constructing three lines from the center LED to the remaining LEDs, then calculating orthogonal distances of LEDs which are not yet on that line to said line, then finding the smallest orthogonal distance to any line, and finally selecting the one LED as flank which is not on the line that is used for finding the smallest orthogonal distance and has not the smallest orthogonal distance to any line, if the center LED is not ambiguous and, - Identifying top and bottom LEDs by constructing a line from the flank LED to the center LED, and identifying the LED on the right side of the line as top LED and left side of the line as bottom LED and switching top/bottom LED correspondences between LEDs in 3D space and their 2D projections if flank LED is on the left side of the LED group and, - Calculating the pose of a tracked object using calculated correspondences between all four LEDs and their 2D projections, - Determining if it is possible to calculate a second pose which also corresponds to the same 2D projection as in the step 107 "calculating the pose of a tracked object", - Switching to a new LED group if all the LEDs in the current LED group are not visible or the center LED is ambiguous or there are two possible poses corresponds to a single 2D projection. - Turning a current group of four LEDs on which is specially placed in a "T" shaped pattern, - Determining if all 4 LEDs in the current LED group are visible by a camera, - Identifying a center LED by calculating distances of all LEDs to other remaining three LEDs and selecting the LED which has the smallest total distance formed by summing up the distances to remaining three LEDs as the center LED, if all the LEDs in the current LED group are visible and - Determining that the center LED is ambiguous if the smallest total distance and the second smallest distance calculated are within predetermined percentage of each other, - Identifying a flank LED by constructing three lines from the center LED to the remaining LEDs, then calculating orthogonal distances of LEDs which are not yet on that line to said line, then finding the smallest orthogonal distance to any line, and finally selecting the one LED as flank which is not on the line that is used for finding the smallest orthogonal distance and has not the smallest orthogonal distance to any line, if the center LED is not ambiguous and, - Identifying top and bottom LEDs by constructing a line from the flank LED to the center LED, and identifying the LED on the right side of the line as top LED and left side of the line as bottom LED and switching top/bottom LED correspondences between LEDs in 3D space and their 2D projections if flank LED is on the left side of the LED group and, - Calculating the pose of a tracked object using calculated correspondences between all four LEDs and their 2D projections, - Determining if it is possible to calculate a second pose which also corresponds to the same 2D projection as in the step 107 "calculating the pose of a tracked object", - Switching to a new LED group if all the LEDs in the current LED group are not visible or the center LED is ambiguous or there are two possible poses corresponds to a single 2D projection.