Microwave from the TV camera, the helicopters only GPS receiver is used to "steer" this antenna towards the receiver on the ground, depending on the location, their may be several ground receivers because you can't shoot through mountains or tall buildings, the correct ground receiver is selected by the pilots GPS. When not lit-up, or broadcasting, that same GPS can be used for navigating the helicopter. In recent years these systems have been upgraded from SD to HD for better picture quality. As can be seen from this picture, the camera can't shoot through the antenna and the antenna can't shoot through the camera.