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 Should we use 1024 or 1200 number of wave samples? What effect does the "mounting height" selection have in the deployment planning? What is the difference between the raw and the processed AST time series? What is the Wave Velocity Cell and how is it used? What is the difference between AST Distance 1 and AST Distance 2 (.WAD)? Comments 0 comments Please sign in to leave a comment.