Ultrasonic Anemometer

Hello,

I have some problems due to transducers received signal shapes. All the transducers receives different shape signals, the lenght and amplitude varies a little bit, so this leads to unstable envelope. This makes me difficult to trigger my envelope detector exactly at the same point for all axis and direction.
How could I solve this?
Do I need to use automatic gain control to set constant amplitude for all received signals? Thank you for any help.