Generalized likelihood ratio detector for forward scattering detection in uncertain shallow-water environments

Forward scattering detection in shallow-water environments presents many challenges, particularly the issues of environmental uncertainties and direct blast, which is an intense sound wave that propagates directly from the source to the receiver without interaction with the target. In this paper, we account for environmental uncertainties and extend the generalized likelihood ratio detector (GLRD) for forward scattering detection in a known environment to uncertain environments. In a suitable bistatic sonar configuration where the source is positioned on the broadside of a large aperture horizontal linear array (HLA), the GLRD exhibits good resistance to direct blast. Moreover, the GLRD demonstrates a certain degree of robustness against environmental uncertainties, particularly when the sampling uncertainty sets of the direct blast/signal wavefront are large enough — including both the real direct blast wavefront and the real signal wavefront. Despite facing the challenge of direct blast in forward scattering detection, the GLRD still performs well in this scenario and demonstrates its effectiveness as a method for forward scattering detection in uncertain shallow-water environments.