Detect 3D Schools dialog box

The Detect 3D Schools dialog box is used to specify settings for detecting schools and creating 3D regions from multibeam data.

To display the Detect 3D Schools dialog box:

Display a multibeam echogram.
On the Echogram menu, click Detect Schools....

Notes:

The Detect button starts detection and closes the dialog box.
Detection can apply exclusion surfaces. See Detecting schools on multibeam data.
The position, size, and shape of detected schools account for transducer geometry.
To view 3D regions, add them to a scene. See About the Scene window.
Region-ping intersections can be displayed on multibeam echograms.
Each 3D region has a 3D Object Properties dialog box, where you can edit its name and appearance and view information about the object.
You can view or delete vacuoles on the Vacuoles page of the 3D Object Properties dialog box.

The Detect 3D Schools dialog box contains these sections:

Pings
Algorithm
3D regions
Configuration

Pings

Select the pings to include in the 3D school detection.

Settings	Description
All pings	Select to include all available pings in the detection. The number in brackets indicates the number of pings.
Ping range	Select to detect schools within the ping range specified by From and To.

Algorithm

Settings

Description

Detection algorithm

Choose a Detection algorithm from the list. The listed algorithms are a function of the ping mode of the current variable:

	Detection algorithm
Ping mode	Cruise scanning	By ping	Instrument scanning
2 (Multibeam)	Y	Y	N
3 (H-mode)	Y	Y	Y
4 (V-mode)	Y	Y	Y
5 (S-mode)	Y	Y	N

Region width (m)

When By ping is selected as the Detection algorithm, specify the width of the detected regions in meters. For other algorithms, this setting is unavailable, but its value is retained.

For By ping detection, each ping is modeled as a zero-width plane. Region width is measured orthogonally to that plane and extends an equal distance on either side.

The Region width value is also used when Detect Schools In This Ping is selected from the multibeam echogram Shortcut menu.

If Region width is too large, regions detected on successive pings may overlap.

If Region width is less than the Minimum shortest dimension specified for schools or vacuoles in the selected multibeam school detection configuration, 3D school detection is not attempted.

3D regions

Settings	Description
Assign class	Select a region class to assign to the 3D regions created by school detection.
Edit Region Classes...	Click Edit Region Classes... to open the Classes page of the EV File Properties dialog box, where you can create a new region class or edit an existing class.
Delete existing 3D regions with this class first	If selected, all 3D regions with the assigned region class within the specified ping range—or throughout the echogram when All pings is selected—will be deleted before detecting 3D schools.
Save vacuoles	Select this to save any detected vacuoles with each created 3D region.

Configuration

Settings	Description
Detection configuration	Select a multibeam school detection configuration from the list. See also About region detection configurations: Preferred detection configuration.
Edit Region Detection Configurations...	Click to display the Multibeam School Detection Configuration Properties dialog box. Settings relevant to multibeam school detection can be changed on this dialog box.
Set as preferred detection configuration for this variable	Select this setting to use the selected Detection configuration to override the preferred configuration on the Regions page of the Variable Properties dialog box.
Detect	Click to start the multibeam school detection process. The detection of schools in large EV files may take some time.

Detect 3D Schools dialog box

Pings

Algorithm

3D regions

Configuration

See also