Energy Sum
In this method, the values in each vertical strip of the spectrogram are summed. The sequence of sums, one sum per vertical strip, makes up the detection function. Energy summation is a useful detection method for scanning sounds to find everything of interest, particularly when the target sounds may be unknown or highly variable. It can also be used as a first step for a more sophisticated multi-step classification system.
Adding the module
From the PAMGuard file menu select Add Modules > Detectors > Ishmael energy sum.
Give a name to the detector, and hit OK.
This detector will require that you also configure a FFT (Spectrogram) Engine as it’s input.
Configure the module
From the PAMGuard Settings menu select Ishmael energy sum Settings … to open the dialog
Select the FFT data source. You should think carefully about the best FFT Length and FFT Hop to use based on the sample rate of your data and the type of sound you are trying to detect. See here for more information on this important, but often overlooked, topic.
Select which channels you want to process and how you want them to be grouped. If channels are in the same group, it’s slightly easier for the PAMGuard localisers to measure time delays between data on the different channels, but only if the hydrophones in each group are quite close together.