About Fish_track_change_in_depth

It reports the Target_true_depth of the last target minus the Target_true_depth of the first target in a fish track region (m). Calculations use the WGS84 datum.

This variable is exported only if it is selected on the Export page of the EV File Properties dialog box.

Warning: If angular position data is unavailable, target_on_axis_depth is used instead of target_true_depth. This is of particular relevance to data collected from a horizontally oriented transducer.

Note: Prior to Echoview 6, this variable used Target_on_axis_depth in calculations.