School Detection Configuration Properties dialog box
The School Detection Configuration Properties dialog box is used to view and edit settings for single beam school detection. Echoview supports 2D school detection configurations, allowing different detection settings to be stored for different hydroacoustic conditions or analysis requirements.
To display the School Detection Configuration Properties dialog box:
- Display the EV File Properties dialog box.
- Click the Region Detection page.
- Under Single beam schools, select a detection configuration and click Properties....
- Click the Single Beam Schools Detection page.
- OR -
- Display the Detect Schools dialog box.
- Click Edit Region Detection Configurations....
- Under Single beam schools, select a detection configuration and click Properties....
- Click the Single Beam Schools Detection page.
Single Beam Schools Detection
You can view and edit school detection settings for 2D echograms:
|
Settings |
Description |
|
Distance mode |
Use the Distance mode list to select the information used to determine horizontal distance for school detection. The selected distance mode affects 2D school detection. The available modes, in the order displayed, are:
The selected mode determines the units used for horizontal settings:
Vertical settings are always expressed in meters. GPS distance, Vessel log distance, Ping number, and Ping time are available when Platform type is set to Position determined by GPS. Ping number and Ping time are available when Platform type is set to Fixed. Water current is available when Platform type is set to Fixed and a Water current speed source is specified. See About speed data. |
|
Minimum total school size |
Specify the minimum horizontal and vertical size of a detected school. After linking is complete, schools that do not meet these minimum sizes are excluded from the detection results. Use the Show time/distance grid to help estimate horizontal school size. |
|
Minimum candidate size |
Specify the minimum horizontal and vertical size allowed for a single school candidate. Use the Show time/distance grid to help estimate horizontal candidate size. |
|
Maximum linking distance |
Specify the maximum horizontal and vertical distances between school candidates that can be linked to form a school. Use the Show time/distance grid to help estimate the horizontal linking distance. Note: The horizontal and vertical linking distances form the semi-axes of an ellipse. The ellipse is effectively moved around the boundary of a school candidate. If any part of another school candidate falls within the ellipse, the candidates are linked. |
Notes:
- Other settings also affect school detection, particularly settings on the Data page of the Variable Properties dialog box and the Exclude above line and Exclude below line settings on its Analysis page.
- Some school detection algorithms make assumptions about the data used for detection and the calculation of corrected school parameters—for example, that only a minimum Sv threshold has been applied. Echoview can filter and condition data in ways that are incompatible with these assumptions, and it cannot automatically identify every situation in which the assumptions are not met. Review the relevant algorithms before interpreting the results.
- School candidates are linked when there is a clear path between them. Valid samples between candidates can prevent them from being linked. If you are confident that particular candidates should be linked, you can include the intervening valid samples in a bad data region and repeat the school detection.
- School detection can be performed while live viewing data or during postprocessing. After detection, region classification rules can be applied.
Name and Notes page
Settings |
Description |
Name |
The unique name of the single beam school detection configuration. In Echoview, name-uniqueness affects platforms, transducers, surfaces, scenes, region class, 3D curtains, 3D regions, lines, sticky notes, region detection configuration, raw variables and unavailable variables. Existing EV files, that contain objects with the same name, will open and affected objects will be assigned a unique name. Potential duplicate names are handled by preserving the source name and appending a bracketed number (e.g., (1)). Valid names for variables and dataflow objects consist of supported characters. These can include text and symbol character encoding and international characters. Commas, double quotes, the vertical bar and the Tab key press are unsupported characters. Where a name is used as the basis of an export file name, any unsupported file name characters are automatically removed. |
Notes |
A text box in which you can enter extra information about the single beam school detection configuration. |
See also
About 2D school detection
Detecting schools on single beam data
Using the School Detection module