Beamformer Configuration
Beamformer Module
Creation and Configuration
Creating a Beamformer module
From the File > Add Modules > Sound Processing menu, select “Beamformer”. Enter a descriptive name for the new module and press OK.
Configuring a Beamformer module
Note: A suitable Source module should be configured before configuring the Beamformer. See below for details of acceptable sources.
From the Settings menu, select “Beamformer settings”. This will open up a new dialog containing 2 tabs: Source and Algorithms.
Source tab
Data Source: where the Beamformer should get it’s input data from. The Beamformer will accept any module that can output FFT information, such as from an FFT Engine module or Decimator module.
Channel Group Type: Select how the channels should be grouped, either No Grouping, a Single Group, or multiple (User) Groups.
Channel Grouping: When a data source is selected, the dialog will show a series of check boxes - one for each channel available from that Source. Select the channels you want to use for beamformer calculation, then to the right of each channel check box, assign the channel to a group. The group numbers themselves are not important - they just need to be different for each group.
The beamformer algorithm will combine the information from all channels in a group and output the resulting signal. If there are multiple groups defined, there will be multiple output signals. In such a case, each signal will be identified by the group number (also termed the Sequence number).
Algorithms tab
The user is able to select a beamformer algorithm for each group defined on the Channel Groups tab. The window displays the group number, and the number of channels associated with that group.
Algorithm: specify which algorithm to use for this group. There are 2 types of algorithms available: Basic Frequency Domain (Conventional/Bartlett) and Minimum Variance Distortionless Response (MVDR). The Basic Frequency Domain beamformer algorithm combines the signals from multiple channels into a single output using a static set of weights. The MVDR also combines the signals from multiple channels into a single output, but uses an adaptive weighting scheme which continuously seeks to minimize the variance of the recorded signal. The MVDR is more processor-intensive, but may result in better noise reduction and signal amplification.
Settings: press the settings button to open up the settings for the algorithm in a new dialog.