horizontal horizontal coordinate system horizontal coordinate system English English English stronomical coordinate systems Altitude and Azimuth English مدخل ویکی درباره سیستم مختصات سمت-ارتفاعی English horizontal English altitude English English http://en.wikipedia.org/wiki/Horizontal_coordinate_system English altazimuth system celestial coordinate English English English altitude and azimuth English English altitude and azimuth क्षितिजीय altitude Alt altitude and azimuth Horizontal Coordinate System altitude English altitude horizontal coordinates