ground control

personnel, system or equipment (stationed on the ground) whose job is to ensure the safe flight of aircraft or spacecraft （保证飞行器安全飞行的）地面导航人员、 系统或设备.

groin, grommet, groom, groove, grooved, groovy, grope, gropingly, gross, gross national product, grossly, grossness, grotesque, grotesquely, grotesqueness, grotto, grotty, grouch, grouchy, ground, ground crew, ground floor, ground rule, ground speed, ground staff, ground swell, ground-bait, ground-nut, ground-plan, ground-rent, grounded, grounding, groundless, groundlessly, grounds, groundsel, groundsheet, groundsman, groundwork, group,