The Likelihood Detector Module

Configuring the Likelihood Detector

Once there is a Likelihood detector module added to the PAMGUARD system, the module can be configured by selecting the Detection-> menu item and choosing the menu option with the name that was supplied when the module was added.

If this is the first time the module has been configured, then a dialog resembling the following will appear.



Likelihood Detector Parameters Dialog



Selecting an Audio Data Source

Located at the top of the Likelihood Detector configuration dialog is the standard PAMGUARD Raw Data Source management panel. Using the drop-down box you can select a single audio source for the module. A Likelihood Detection module can only have one audio source. If you would like to process multiple target configurations on multiple audio sources simultaneously, you will need to add another Likelihood Detection module. See the section on adding a new Likelihood Detection module for more information.

You can also select which channels of audio data to process. By default, all channels will be selected, but by using the checkboxes you can filter out specific channeles.



Selecting an audio source



Adding a Target Configuration

To add a new target configuration to the Likelihood Detector module, right-click on the "Target Configurations" row in the list box and select "Add Configuration".



A dialog box will open and prompt you to enter a unique name for the target configuration. The dialog will not allow you to enter in a name that is already taken. Note that target configuration names are case sensitive.



General Parameters

Once a target configuration is added, it will be displayed in the configuration area, showing the default values for the general parameters. These general parameters are discussed in brief below.





Parameter Tooltips

Most of the target configuration parameters have legal bounds that are determined either by the audio data source's parameters or by other target configuration parameter values. In order to ease configuration of the Likelihood Detector module, tool tips are provided in the configuration dialog. Leaving the mouse pointer over a parameter's value in the Value column of the dialog's target configuration window will display a tool tip indicating the valid lower and upper bounds for a parameter. The bounds displayed by the tool tip will be enforced by the editing widget for the parameter.



Showing a parameter's tool tip

Note: Some parameters are co-dependent, for example the signal/guard band's noise window and the signal window. To be able to enter the value you want, it may be necessary to alter a dependent parameter. The tool tips will help you with this by explaining if any parameter boundries are dependent on another parameter.

Editing a Parameter

All of the configurable parameters for a target configuration are editable in-place within the configuration dialog. To edit a parameter, simply double-click with the left mouse button on a value in the Value column and an editing widget will appear.

The editing widget for a parameter will enforce the valid values on the numbers that are entered.



Editing configuration parameters

Note: Some parameters are co-dependent, for example the signal/guard band's noise window and the signal window. To be able to enter the value you want, it may be necessary to alter a dependent parameter. The tool tips will help you with this by explaining if any parameter boundries are dependent on another parameter.

Parameter Validation

The Likelihood Detector's configuration dialog provides validation of user input. When a tool tip displays a range of valid values (see Parameter Tooltips, above) the configuration dialog will give live feedback to the operator by disallowing invalid characters and values to be entered. This feature works in conjunction with the error reporting described below.

The Java Validator used to implement the validation can be very literal with what it allows you to type. Here are some helpful hints to keep in mind when entering floating-point values:


Note: Some parameters are co-dependent, for example the signal/guard band's noise window and the signal window. To be able to enter the value you want, it may be necessary to alter a dependent parameter. The tool tips will help you with this by explaining if any parameter boundries are dependent on another parameter.

Error/Warning reporting

When a new target configuration is added, or when all of the signal bands for a target configuration have been removed, the target configuration isn't valid. Since a configuration isn't valid without at least one signal band, the target configuration selection box will display a red border prompting you to add a signal band.



Invalid configuration error with tool tip showing


While editing a target configuration parameter, if the text entered isn't valid or is not within the allowed legal boundries for the parameter, then the configuration dialog will display a red border around the parameter's editor and keep the editing focus there until a valid value is entered.



A parameter error while editing


Since many of the target configuration's parameters have legal boundries based on audio data source parameters or on other configuration parameters, it is possible that a change to a parameter will invalidate some other parameter in a target configuration. In addition, a change to an audio data source may invalidate values in one or more whole target configurations.

If this condition occurs, then the existance of invalid parameter(s) will be indicated in two ways:

A parameter dependency error


In certain cases, a value can be within an accepted range, but it will produce an undesirable result. For example, the Noise Window parameter of the signal and guard bands will produce a warning if it is set to a value that is greater-than or equal to the time resolution times 500. In this case, the warning is provided to make the user aware of the increased processing load that would be required.



When a warning condition is detected, the configuration dialog will change the background of that parameter to yellow:



A parameter warning



Adding a Signal Band

To add a new signal band to a target configuration, right click on the Detection Bands tree item for the name of the target configuration you wish to add a new band to, and a pop-up dialog will appear. Select the Add Signal Band menu option. You will be prompted to add a new unique signal band identifier for the target configuration. The band name dialog will ensure that the identifier you choose is unique.



Adding a signal band

Signal Band Parameters

When a new signal band is added, the Likelihood Detection module will add a series of default parameter values for the band.The default thresholds should be acceptable for most environments but can be lowered if the detector has too many missed detections, or raised if the detector is generating too many false detections. These are shown and described below:



Signal band parameters





Adding a Guard Band

To add a new signal band to a target configuration, right click on the Detection Bands tree item for the name of the target configuration you wish to add a new band to, and a pop-up dialog will appear. Select the Add Guard Band menu option. You will be prompted to add a new unique signal band identifier for the target configuration. The band name dialog will ensure that the identifier you choose is unique.



Adding a guard band



Guard Band Parameters

When a new guard band is added, the Likelihood Detection module will add a series of default parameter values for the band. The default thresholds should be acceptable for most environments but can be lowered if the detector has too many missed detections, or raised if the detector is generating too many false detections. These are shown and described below:



Guard band parameters





Enabling and Disabling a Target Configuration

A single Likelihood Detection module can have many different target configurations configured, but not all of them need to be active during a detection run.

Enabling and disabling a target configuration is as easy as selecting the target configuration checkbox located next to the name of the target configuration in the configuration tree.



An enabled target configuration



A disabled target configuration



Various target configuration states



Removing a Signal or Guard Band

Removing a signal or guard band from a target configuration is easy. Simply right-click on the name of the band you wish to remove, and a pop-up menu will display an option to remove the band.



Deleting a signal band



Deleting a guard band



Removing a Target Configuration

If you wish to completely remove a target configuration from a Likelihood Detection module, right-click on the name of the target configuration you want to remove. A pop-up dialog will appear, providing you with the option to delete the configuration.



Deleting a target configuration




Next: Importing and Exporting Target Configurations

Previous: Adding a New Likelihood Detection Module