In 1800, the British astronomer F.W. Herschel discovered infrared light. The practical application of infrared technology in the military began during World War II. At that time, Germany developed and used some infrared technology equipment, including infrared communication equipment and infrared night vision devices, all of which belonged to active infrared systems. After the war, due to the rapid development of infrared photon detectors and infrared-transmitting optical materials, the application of infrared technology attracted the attention of military departments. Since then, the development direction of infrared technology has focused on passive systems. In the 1950s, infrared point source guidance systems were used on tactical missiles. In the 1960s, the military application of infrared technology has been quite extensive, such as has been used in guidance, fire control, targeting, reconnaissance and surveillance. In the mid-1960s, the infrared imaging technology of opto-mechanical scanning appeared. In the 1970s, infrared imaging technology developed rapidly, and the application of thermal imaging systems and charge-coupled devices was an important achievement in this period. In the 1980s, infrared technology entered a new period of developing mosaic focal plane array (CCD array) systems.