Detecting fish tracks

Fish track detection can be carried out on a selection or on the entire single target echogram. The single target echogram can either be a raw variable or a virtual echogram. See About single target detection for more information.

Echoview offers the choice of two fish track detection algorithms:

  • The 2D algorithm uses the range and time information of the single targets.

  • The 4D algorithm is intended for use with split beam data and uses the angular position information of the targets in the beam in addition to the range and time.

Before you begin

The display thickness of single targets will affect fish track detections. Fish track regions will be drawn around entire single target display thickness. See Configuring single target display thickness for information about changing the display thickness of single target detections.

Note: The single target variable needs to have at least two pings for a fish track detection.

How to detect fish tracks

To detect fish tracks in a selection of an echogram:

  1. Bring the single target echogram into focus.

  2. Make a selection using one of the selection tools.

  3. On the Shortcut menu (right-click), click Detect Fish Tracks to launch the Detect Fish Tracks (Selection) dialog box.

  4. On the Detect Fish Tracks (Selection) dialog box, using the Assign class list, select a region class to assign to the detected fish tracks (click Edit to create a region class if required).

  5. If you want to delete fish tracks of the chosen class from the selection prior to detecting fish tracks, select the Delete existing fish tracks with the assigned class first option.

  6. In the Detect Fish Tracks (Selection) dialog box, click Properties to launch the Track Detection Properties dialog box.

    • On the Algorithm tab, choose a detection algorithm and enter other detection settings as required. See the Algorithm page for more information.

    • On the Weights tab, enter required weight settings. See the Weights page for more information.

    • On the Track Acceptance tab, enter required track acceptance settings. See the Track Acceptance page for more information.

  7. Click OK to close the Track Detection Properties dialog box.

  8. On the Detect Fish Tracks (Selection) dialog box, click Detect.

To detect fish tracks in the entire echogram:

  1. Bring the single target echogram into focus.

  2. On the Echogram menu, click Detect Fish Tracks.

  3. Navigate the procedure from step 4 in the above list.

Once fish track regions have been drawn, it is possible to graph fish tracks, analyze single fish tracks, export fish track analyses, edit fish tracks and create 3D fish tracks.

See also

About fish track detection
About fish track regions
Fish tracking algorithms
About beam geometry
Exporting fish track analyses
Fish Track Analysis dialog box
Detect Fish Tracks dialog box
Fish track editing
Configuring single target display thickness
COM EvVariableAcoustic.DetectFishTracks