We have actually decided to not measure along beam velocity for the vertical beam on the AWAC. The reason for this is that the three beams at an angle are sufficient for determining the 3D flow during the current profiling mode and more importantly we do not transmit on this transducer and thus save 30% power during current profiling.

The reason we have the vertical pointing beam is for the Acoustic Surface Tracking which would not really work that well for the non-vertical beams. In wave mode the transducer is dedicated for AST and not the velocity.

The Signature 500 and 1000 can measure velocities along the fifth (vertical) beam. When comes to turbulence studies, we have found the velocimeter or the Signature series to be better instruments because of its (a) higher sampling rate, (b) smaller measurement volume, c) measurements are not spatially separated as with a current profiler.