We are currently experimenting with nano-particle coatings that claim to drastically reduce water droplets and snow sticking to SKY.
When first installed, SKY will go through a self-balancing routine to ensure the sonic transducers are correctly aligned — critical for timing of sonic signals and determination of wind speed. See SKY / Tempest: wind sensor initial self balancing.
Wind direction is determined by the user installation. Point the “N” marking on the side of the SKY device facing directly North. (Tip: use a compass app on your phone to determine North.)