A vehicle closure assembly includes a vehicle body defining an opening, a latch assembly mounted to the vehicle body, a track mounted to the vehicle body, a slidable closure movable with respect to the vehicle body for selectively covering the opening, and a roller and striker assembly connected with the slidable closure for movement with the slidable closure. A system and a computer software code linking together two or more powered systems to operate as a single distributed power system are also disclosed. The inverted F antennas are arranged on, or in, a plane. Alternatively, the zeroth order of signal light is selected for measurement, or a spatial coherence length of the probe light is compared with the degree of fineness of the pattern on the surface illuminated with the probe light.