Here's a
description of DIANE :
DIANE System
Digital Integrated Attack Navigation Equipment
AN/APQ-92
Main search radar, provide both a navigation and attack facility
AN/APQ-122
Tracking radar for terrain mapping and traget location
AN/APN-141
Low altitude (up to 1524m -5000 ft) radar altimeter
AN/APN-153
Doppler radar for navigation and to provide ground speed and drift angles for ballistic computer
AN/ANS-31
Inertial navigation system, provide data on heading altitude and horizontal and vertical velocities
AN/ASQ-57
Integrated electronic control system
AN/ASQ-61
Ballistic Computer, provides flight pattern data, cruise control and data for weapons selection, fuzing and delivery
AN/ASW-16
Three axis autopilot
AN/AVA-1
Pilots display unit, provide data on flight parameters, such as terrain clearance
CPA-728A
Air data computer which provides altitude static pressure, Mach number and airspeed information for the ASW-16, the AVA-1 and the conventional flight instrument
I have to say I don't envy the avionics programmer, although I'm sure a lot of it can be abstracted in the game.