Power Beamforming in NoiseImage
In real measurement environments the sound field often consists of overlays of several independent individual sound sources. Conventional beamforming methods such as the Frequency-Domain Beamforming (FDBF) usually achieve rather low dynamics and resolution, depending on the array used. The distinction between the main and side lobes can be made more difficult, so that the sources in the acoustic photo can be mapped with difficulty or not at all separated from each other.
The solution is the new "Power-Beamforming" option in NoiseImage's advanced algorithms. The eigendecomposition of the cross-spectral matrix leads to the division of the acoustic map into individual pseudo sources and their point spread functions (PSF). Several algorithmic approaches are combined, which are all based on the same calculation principles: Functional beamforming, asymptotic beamforming, inverse functional beamforming and adaptive beamforming. The different stages of power beamforming cause attenuation of the side lobes and sharpening of the main lobes. Overall, the dynamics and sharpness are increased and the sources can be separated.
Further information about our software can be found on acoustic-camera.com.