Side-looking Vectrino probes

The 4D side-looking probe has four beams, two in the horizontal and two slanted 65 degrees from the vertical.  With the two horizontal beams we form the Vx and Vy velocity.  This means that we don't need the slanted beams to measure the horizontal velocity, which means that the probe can act as a 2D system even in shallow water.  As the water gets deeper, the last two beams are covered and we then combines the information from all four beams to measure the vertical velocity Vz.  However, there is no meaningful way to form two independent Vz estimates from the four beams so in the Vectrino software we simply set "Vz2" to zero.

We still report the SNR and COR for all four beams since these values refer to the invidual beam measurements and not the transformed velocity data.  

 Best regards, Atle Lohrmann

I have just recently been able to test out the side-looking probe (with
the Vectrino +) that Eric sent us. However, when I was taking
measurements with it, the Z2 signal was flatlined. I had active signals
for the X, Y and Z signals, and they made sense. I know the sensor
orientation is different with the side-looking probe, but I didn't know
if the Z2 signal was intentionally neglected for this probe.

If there is no Z2 signal, why? I don't really need it since I have Z,
but since you have 4 sensors on there, it seems like you would take it.
The header file that is included with the data still lists Z2 and it's
counterparts (Z2 SNR, Z2 Correlation, etc).

If there is supposed to be a Z2 signal and there wasn't, do you know
why? I did attach the side-looking probe in the same manner as the
downward looking probe and my signals for X Y and Z were strong and
logical. Is there a manufacturing defect with the probe or could it be
a software issue? Would a malfunction in Z2 void our results for the
other 3 signals?