Originally Posted by
Looigi
No. The ports are on the bottom of the unit, more or less perpendicular to flow, so would be static pressure. For stagnation pressure, the port would have to be pointed directly into the air flow.
For static pressure you need a sensor that is on the outside of the unit. Garmin has a system of channels inside the mount that terminate at the intake port. There could be lines of flow that terminate inside the port. I guess it depends on the exact geometry.
It should be very easy to test. If Garmin normally measures stagnation pressure (as mounted on the bike), it has to do velocity correction. If it does velocity correction, it should immediately show up as a jump in elevation if you turn it on inside a car that accelerates from stand still to the freeway speed (you may need to crack rear windows to equalize pressure).