About speed data

A speed variable is a time series of the water current speed, and is derived from speed data added to a fileset. The variable can be used with a fixed platform.

What is affected by speed data?

Calculation of distance from speed data

Equation for distance based on speed data

Where:

dLatest is the latest distance (m)

u is speedLatest the latest speed (ms-1)

t = timeLatest - timePrevious is the difference between the latest and previous times (seconds)

a = (speedLatest - speedPrevious)/(timeLatest - timePrevious) is the acceleration between the latest and previous speeds (ms-2)

dPrevious is the previous (cumulative) distance (m)

Notes:

  • When the ping time is before the first speed datum, the first speed datum of the speed variable is used.
  • When the ping time is after the last speed datum, the last speed datum of the speed variable is used.

See also

Exporting speed data
Speed graph
Speed data file format
Platform Properties dialog box
2D school detection
Fish tracking