We do two checks; one based on standard deviation and one acceleration check.
We start by calculating the standard deviation of the time series of the AST. Then we reject the samples that are outside 8 times standard deviation (more information here). We repeat this process after removing the out-layers at the same time as we reduce the n-times standard deviation criteria. We repeat until we've reach 4 times standard deviation.
The acceleration check is confirm if the change of wave height is physically possible taking gravity into consideration. It is a check to ensure the vertical change for a given sample rate does not exceed the acceleration of gravity.
After filtering out data that has not passed these checks, the gaps created by the removed outliers are linearly interpolated with each iteration quality control.