Two Phenomena in Forward Scattering Experiments

Recent processing of earlier obtained experimental data has revealed two phenomena making it possible to obtain necessary and sufficient conditions for detecting a forward scattering signal with the best efficiency. The location object should intersect one of the rays connecting the emitter and the receiver without touching the water surface. This is the basis of the first phenomenon: significant (more than 100-fold) compression of the detected signal. The second phenomenon is that the noise background surrounding the detected signal is a type of noise formed by an uneven bottom relief. This noise does not generate false alarms and is physically similar to speckle noise in optics. It is demonstrated that additive noise is primarily formed by signals scattered by a rough lake surface and that this noise is weakly suppressed when detecting the useful signal; however, it can be eliminated by imparting directivity to the illuminating signal source. All other noise is completely suppressed.