A satellite dish antenna may be roof-mounted or may be installed on the ground. If roof-mounted, the satellite dish antenna shall not exceed 40 inches in diameter, shall not extend more than four feet above the roof line where mounted, and shall be located toward the rear of the structure away from the street line. If mounted on the ground, the satellite dish antennae shall not exceed 12 feet in diameter, shall not extend more than 15 feet above the ground level, and shall be located in the rear yard areas only. Moreover, each ground-mounted satellite dish antenna shall be set back a distance equivalent to the diameter of the dish antennae or the setback requirements specified for accessory structures in the zone in which the antenna is located, whichever distance is greater.