Editing Lockheed F-104 Starfighter (section)

===Avionics===

[[File:Radar dish of a F-104 Starfighter.JPG|thumb|alt=Museum display of an exposed F-104 radar dish|NASARR [[radar]] on F-104]]
The initial USAF Starfighters had a basic RCA AN/ASG-14T1 ranging radar, [[tactical air navigation system]] (TACAN), and an AN/ARC-34 UHF radio. The AN/ASG-14 fire control system used a {{convert|24|in|adj=on}} pencil-beam radar antenna with two independent sights: one optical and one infrared. Early versions of the radar had a range of approximately {{convert|20|mi}} in search mode, with later models reaching up to {{convert|40|mi}}; the scan pattern was spiral, covering a 90-degree cone. Search mode was usable only above {{convert|3000|ft}} due to ground return effects below that altitude. Track mode was usable within {{convert|10|mi}} of the target, which narrowed the scan to 20 degrees and initiated a strobe sweep between {{convert|300|and|3000|yd}} in auto-acquisition mode. The radar also had a third, receive-only mode useful for locking onto sources of interference from [[electronic countermeasures]] (ECM).<ref name="Davies2014p13">Davies 2014, p. 13.</ref>

In the late 1960s, Lockheed developed a more advanced version of the Starfighter, the F-104S, for use by the Italian Air Force. Similarly to the F-104G, Lockheed produced two main variants of the F-104S: an all-weather interceptor (''caccia intercettore'', CI) and a strike aircraft (''caccia bombardiere'', CB). The CI variant received a FIAR/NASARR F15G radar with AIM-7 Sparrow guidance capability; however, the new missile-guidance [[avionics]] came at the expense of the M61A1 Vulcan cannon, which was removed to make room. The CB variant was equipped with a FIAR/NASARR R21G-H radar and a radar altimeter for low-level strike missions, retaining the cannon as its only air-to-air weapon.<ref name="Dobrzyński2015p51">Dobrzyński 2015, p. 51.</ref>

As part of the ''Aggiornamento Sistema d'Arma'' (ASA), or "Weapons System Upgrade" in the mid-1980s, both variants were given an ALQ-70/72 ECM and a FIAR/NASARR R-21G/M1 radar with [[frequency hopping]] and [[look-down/shoot-down]] capability. The new radar and guidance systems enabled the aircraft to carry the new AIM-9L Sidewinder infrared-guided missile (replacing the older AIM-9B) as well as the AIM-7 Sparrow and the [[Selenia Aspide]] radar-guided missiles.<ref name="Dobrzyński2015p52">Dobrzyński 2015, p. 52.</ref>