Chain Home Low (CHL) was the name of a radar system used by the RAF during World War II. The official designation was AMES Type 2 (Air Ministry Experimental Station). It was based on CD (Coastal Defence) and CA (Coastal Artillery) radar designed for army use. It was noticed that these were able to detect low-flying aircraft and so led to the development of CHL for the RAF. It operated on a shorter wavelength than Chain Home, about 1.5 metres.