About Target_on_axis_depth

It reports the on-axis depth of a single target (m). This variable takes transducer geometry into account but not beam geometry. It is NOT the Target_true_depth. Calculations use the WGS84 datum.

See About single target depths for further information.

This variable is exported only if Depth is selected under Echogram mode on the Echogram page of the EV File Properties dialog box.

Note: Prior to Echoview 6, this variable was known as Target_depth.