Building it is half the battle. It also has to calibrated which is done in a wind tunnel. Wind angles for all directions (both laterally and vertically) have to

Building it is half the battle. It also has to calibrated which is done in a wind tunnel. Wind angles for all directions (both laterally and vertically) have to be tested to see which measurements need to be adjusted to account for the interaction of the wind with the sensor itself. Wind speeds have to be similarly tested. For a one-off sensor, this is expensive. Less so if you make thousands of the same design.