The Bad Aibling Station (BAS), also known as the 18th United States Army Security Agency Field Station, Field station 81, and Hortensie III is a satellite tracking station operated by the German SIGINT agency BND from nearby Mangfall Barracks in Bad Aibling, Bavaria.

The Federal Intelligence Service is the foreign intelligence agency of Germany, directly subordinate to the Chancellor's Office. The BND headquarters is located in central Berlin. The BND has 300 locations in Germany and foreign countries. In 2016, it employed around 6,500 people; 10% of them are military personnel who are formally employed by the Office for Military Sciences. The BND is the largest agency of the German Intelligence Community.