Surface backscattering statistics for observations conducted near Kiel, Germany

In May 1993, an experiment was performed off the coast of Kiel, Germany to study the temporal variability of backscattering from the ocean boundaries. In the sea-surface backscattering component of the experiment, two dual-mode acoustic transducers were used to ensonify the surface with 1 or 3 ms pings at 20–90 kHz and incident angles of 65.1°−80.9° from normal. The transducers also recorded the backscattered sound. Analysis of the overall returns shows that they vary significantly from ping to ping, such that the distribution of backscattered energy appears nearly Gaussian. However, close comparison of all the signals from a given run indicates the presence of strong salient patterns in some cases, which suggest scattering from individual features (presumed to be wave crests) which move through the beam pattern from ping to ping. The statistics of the backscattered signal from these features, and their relation to the overall backscattered energy statistics, is the topic of this paper. [This work was funded by the Office of Naval Research.]