Towed body correction

Loading and viewing > Calibration > Background noise-removal > Detection and filtering > Classification > Characterization

If a transducer is mounted on a towed body, variations in the depth of the transducer during the survey will be embedded in the data. An otherwise flat bottom may appear inclined or undulating depending upon the vertical motion of the transducer while sounding. If the depth of the towed body is monitored and recorded it can be used in Echoview to correct the echogram data.

The Echoview Towed body operator (with usage caveats) may be useful for downward facing transducers mounted on a towed body.

Depth information may also be applied using the Heave source setting on the Platform Properties dialog box. This is preferable to using the Towed body operator. See also: About heave compensation.


Towed body


Towed body dataflow

Dataflow object


Echoview feature

Fileset1: Sv raw pings T1

Sv data from transducer on the towed body

Raw variable

Bottom line

Use recorded depth-variation data to model a line that may be used for towed body correction. Import the data as an Echoview line definition file.

When logged depth-variation data is absent, use the line pick process to estimate an acoustic bottom line. Export the line to a .csv file to find the deepest depth for the line.

Editable line

Surface line

Create a Surface line based on the Bottom line. Multiply by -1 and add the value for the deepest depth variation.

Editable line

Towed body 1

Use the Surface line to correct Sv data from the towed body.

Towed body operator


See also

Virtual variable applications
Synchronizing towed media data with echograms