I've tried searching online as to what the architecture of these systems look like, and I can't seem to find any hardware information. And if it's not a hardware but instead a software, which software uses it and how do you know if you have it?
As far as I know, in the DA40 with G1000 that my flight school flies, we do not have either Baro-Aiding or Baro-VNAV. I understand roughly how they work, but I have yet to find an example of a system that has either. Can someone provide examples of systems that do utilize Baro-Aiding or Baro-VNAV?