Track analysis parameters

Track3D calculates a wealth of track analysis parameters from the recorded x,y,z coordinates of the animal's movement trajectory. Each set of coordinates constitutes a single data point.  
For each such data point and the track connecting all data points, the following parameters are obtained.

Parameters of distance, tortuosity and speed 

  • Total distance moved in the 3D space
  • Horizontal distance moved
  • Vertical distance moved
  • Tortuosity (distance moved divided by the distance between start and end points). Tortuosity measures the amount of turns in the trajectory. Tortuosity is also calculated horizontally and vertically.
  • Instantaneous velocity vector, calculated as the derivative of a cubic spline function fitted through the adjacent data points
  • Measurements of backward/forward, lateral and vertical displacement
  • Component of the instantaneous velocity vector in the horizontal plane; for measuring displacement relative to the ground

 Parameters of heading

  • Angle of the animal’s instantaneous velocity vector with the x direction
  • Angle in the horizontal plane between the component of the instantaneous velocity vector and the x direction; for measuring deviations from forward/backward displacement
  • Angle in the vertical plane between the component of the instantaneous velocity vector and the x direction; for measuring deviations from horizontal displacement
  • Intended headings (that is, the above angles corrected for the speed and direction of the air flow, if present)
  • Drifts in different planes (the difference between heading angles and intended headings)

Parameters of angular change and velocity

  • Change in heading from one data point to the next, in the 3D space (see Figure 3) and in different planes
  • Change in headings per time unit, in the 3D space and in different planes

Analysis in relation to 3D zones

  • Data can be visualized in relation to the position of the animal relative to the estimated position of the odor plume in the test chamber (applies mainly to insect orientation studies)
  • Data can be filtered in relation to the position of the animal relative to a user-defined 3-D zone (cuboid or cylinder).