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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?

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Many corporate jets use a baro-aided VNAV system. Before WAAS was so prevalent, many FMS installations were certified to TSO c129 standards allowing the operator to fly RNAV GPS approach procedures to both LNAV and LNAV/VNAV minima.

Universal, Collins and Honeywell all have FMS hardware that use the onboard ADC to calculate a psudo glidepath the FMS can project as a VNAV path on the PFD.

I don't know if Garmin ever had a system that uses baro-aided glidepaths.

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As mentioned on previous answers, Baro-VNAV system combines lateral GPS position with barometric altitude.

The approach is retrieved from navigation system database which includes the MAPt position and elevation and required glide slope angle. Combining the two, the system is able to calculate the required altitude respective to the aircraft position.

The deviation between desired altitude and aircraft’s indicated altitude is displayed as deviation in a similar fashion to ILS glide. But because the glide slope is calculated onboard, it is prone to errors such as aircraft position (wrong distance to the MAPt), wrong QNH setting and cold temperatures.

Baro-VNAV is available in any modern transport category aircraft.

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They are a combination of software and hardware. The GPS must have access to an altitude encoder or static source to use baro-aiding or baro-VNAV. It also must be equipped with software that can take advantage of the altitude source to provide vertical guidance on an approach.

The capabilities of G1000s varies by aircraft. For example, some G1000-equipped King Airs are capable of baro-VNAV.

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