The AN/APG-63 and AN/APG-70 are a family of all-weather multimode radar systems designed by Hughes Aircraft (now Raytheon) for the F-15 Eagle air superiority fighter. These X-band pulse-doppler radar systems are designed for both air-air and air-ground missions; they are able to look up at high-flying targets and down at low-flying targets without being confused by ground clutter.
The systems can detect and track aircraft and small high-speed targets at distances beyond visual range down to close range, and at altitudes down to treetop level. The radar feeds target information into the aircraft's central computer for effective weapons delivery. For close-in dogfights, the radar automatically acquires enemy aircraft and projects this information onto the cockpit head-up display.
The APG-63 was developed in the early 1970s and has been operational since 1973, and was installed on all F-15 A/Bs. In 1979, it received a major upgrade and became the first airborne radar to incorporate a software programmable signal processor (PSP), and the PSP allowed the system to be modified to accommodate new modes and weapons through software reprogramming rather than by hardware retrofit. The APG-63 with PSP is one of the most important feature that disguishes earlier F-15 A/Bs from the F-15 C/Ds it arms, and with the exception of the final 43 (which is armed with APG-70), all F-15 C/Ds are armed with APG-63 with PSP.
The APG-70 was a 1980s redesign of the APG-63 for greater reliability and easier maintenance. Additionally, gate array technology enabled the APG-70 to incorporate new modes with enhanced operational capabilities. To reduce production costs, many of the upgraded radar's modules are common with the APG-73 (F/A-18) radar, while the computers / processors are 85% in common with that of APG-71 (F-14) radar.