Fig. 8

Tag orientation correction user interface. A For this example, a friendly minke whale (bb190309-52, also see Figs. 6, 12) approaches directly at the tagging boat, resulting in a tag on the whale in reverse orientation from the whale’s natural axes (see Fig. 4). B Step one is to identify the approximate locations of tag slips. Exact times can sometimes be seen on tag videos, or can be inferred from where the tag’s surface accelerometer values change. C Cell 8 of MainCATSprhTool.m facilitates zooming in on tag data to identify likely tag slips, often corresponding to rapid changes in acceleration of the tag (increased jerk, see [38]). D In cell 8b, when tag frame is rotated to whale frame (Fig. 7), the calculated pitch, roll or heading can be used to indicate probable tag slip locations as well, as a discontinuity is often a sign of a tag slip. E User selected surfacings and dives (Fig. 7A, B) give immediate feedback to the user on the final rotated frame of reference (Aw), as well as the calculated animal pitch and roll. In this example, the x-accelerometer is rotated from backwards to forwards (aligned with the whale’s frame of reference), with very few changes to the y- or z-axes. Pitch, roll and Aw are not yet calculated for the red highlighted period after the first tag slip