The Gate Park System consists of two guidance elements mounted at the gate in front of the aircraft, plus an operator's control switch
The lateral guidance element consists of an aluminum housing and shade
hood which support a pair of vertical, Light Emitting Diode (LED) light bars, one red and one green.
The LED light bars are mounted fore and aft of each other on the same axis such that when the pilot is positioned directly in front of the LED bars, only green is visible. As deviation to left or right increases, the rear mounted (red) LED light bar is no longer shielded by the green LED light bar, making red visible. The red LED light bar would be visible to the left of the green LED light bar if, for instance, the aircraft drifted to the left of the taxi line approaching the gate.