Japan’s military scrambled fighter aircraft to intercept Russian Ilyushin Il-20M radar reconnaissance and electronic intelligence aircraft, it said on 14 August.

According to the statement, Japan scrambled fighter jets on Friday to warn Russian IL-20M (RF-75936) warplane it said had entered its air space identification zone over the neutral waters of the Sea of Japan.

The Ilyushin Il-20M is an upgraded electronic signals intelligence aircraft based on a 1950s-era turboprop-powered plane. Spy plane carries a wide array of antennas, optical and infrared sensors, and side-looking radar, as well as satellite communication equipment.

Electronic signals intelligence, or ELINT refers to intelligence-gathering by use of electronic sensors.

Signal identification is performed by analyzing the collected parameters of a specific signal, and either matching it to known criteria, or recording it as a possible new emitter. ELINT data are usually highly classified, and are protected as such.

The data gathered are typically pertinent to the electronics of an opponent’s defense network, especially the electronic parts such as radars, surface-to-air missile systems, aircraft, etc.