@Noob21 While I can't find any evidence in the 600 page avionics manual that this is the exact technique used in the Starship, the end result should be the same. The two DME-442 "three channel transceivers" (in addition to the two other NAV receivers) are constantly tuning and receiving DME stations. I thought you might enjoy the detail presented by the Starship's avionics manual, despite not containing the answer we were looking for:
"The digital synthesizer originates the CW frequency
used to drive the power amplifier. The processor programs
the synthesizer with the tune frequency using
data, clock, and enable lines decoded from the data
buffer bus. This dc level tunes the veo to apply
the proper CW interrogation frequency to the power
amplifier. The vco also supplies VAR FREQ feedback
to the synthesizer, which is compared with a fixed
REF frequency to provide error correction."
I have emulated all of these navigation sources to the best of my ability, within reason and performance limitations, using the resources at my disposal within MSFS. When you select which navigation sources to use, the aircraft's positional estimate will improve or degrade depending on how well these sources are being received. Although I have not come up with a convenient way for this to influence the autopilot, and thus the course flown (I am still thinking of ways to do this), you will be able to monitor the status of the FMS position, and the operation of all these receivers, and receive notifications and flags when the FMS loses confidence in its position, just as in the real aircraft.
