Does the AST measure distance from effectively the same point on the instrument as the pressure sensor? Nortek Support June 22, 2019 13:39 Updated Follow Yes, the pressure reading and the AST distance has been calibrated so that they both have the same distance. Related articles What is the Wave Velocity Cell and how is it used? What is the difference between the raw and the processed AST time series? My instrument is not communicating. What should I do next? What is the minimum deployment depth for an AWAC? Quick Guide – Signature250, 500 and 1000 Comments 0 comments Please sign in to leave a comment.