Image processing for activated towed array sonar displays

Display concepts for activated towed array sonar systems (ATAS) often differ from the well known PPI-displays, where the so called echogram display is used. It is shown how normalisation filters influence the reverberation patterns or texture of these diagrams, respectively. First order histograms of the displays are utilised to keep the brightness of the images, independent of the processing parameters e.g. the normalisation window length. Second order spatial histograms are calculated to quantify the texture features of the obtained images. It is shown how these techniques can be applied to support human pattern recognition