About Tortuosity_2D

Tortuosity_2D is an analysis export variable available in exported fish track analyses.

It reports the tortuosity (sum of the distances in a track divided by the distance from the first to last target in the track) of a fish track region, measured in 3 dimensional space, but ignoring angle data (-).

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

Notes:

The _2D_ fish track analysis variables use only time and range information (ignoring angle data if present). All targets are treated as if they lie at the center of the acoustic beam. The _3D_ and _4D_ fish track analysis variables use, time, range, and minor and major axis angular position information.
Under a fixed platform, consider using Heading source: Fixed heading (north) for a more appropriate reference for fish track distance and speed calculations. For more information refer to About fish tracks: Notes.

About Tortuosity_2D

See also