FN Archimer Export Format PT J TI Processing of high-frequency multibeam echo sounder data for seafloor characterization BT AF HELLEQUIN, Laurent BOUCHER, Jean-Marc LURTON, Xavier AS 1:2;2:2;3:1; FF 1:;2:;3:PDG-TMSI-AS; C1 IFREMER, TMSI AS, F-29280 Plouzane, France. ENST Bretagne, F-29285 Brest, France. C2 IFREMER, FRANCE ENST BRETAGNE, FRANCE SI BREST SE PDG-TMSI-AS IN WOS Ifremer jusqu'en 2018 IF 0.55 TC 111 UR https://archimer.ifremer.fr/doc/2003/publication-708.pdf LA English DT Article DE ;Seafloor classification;Multibeam echo sounder MBES;K distribution;Backscatter model AB Processing simultaneous bathymetry and backscatter data, multibeam echosounders (MBESs) show promising abilities for remote seafloor characterization. High-frequency MBESs provide a good horizontal resolution, making it possible to distinguish fine details at. the water-seafloor interface. However, in order to accurately measure the seafloor influence on the backscattered energy,the recorded sonar data must first be processed and cleared of various artifacts. generated by the sonar system itself. Such a preprocessing correction procedure along with the assessment of its validity limits is presented here and applied to a 95-kHz MBES (Simrad EM1000) data set. Beam pattern effects, uneven array sensitivities, and inaccurate normalization of the ensonified area are removed to make possible further quantitative analysis-of the corrected backscatter images. Unlike low-frequency data where the average backscattered energy proves to be the only relevant feature for discriminating the nature of the seafloor, high-frequency MBES backscatter images exhibit visible texture patterns. This additional, information involves different statistical distributions of the backscattered amplitudes obtained from various seafloor types. Non-Rayleigh statistics such as K-distributions are shown to fit correctly the skewed distributions of experimental high-frequency data. Apart from the effect of the seafloor micro-roughness, a statistical model makes clear a correlation between the amplitude statistical distributions and the signal incidence angle made available by MBES bathymetric abilities. Moreover, the model enhances the effect of the first derivative of the seafloor backscattering strength upon statistical distributions near the nadir and at high incidence angles. The whole correction and analysis process is finally applied to a Simrad EM 1000 data set. PY 2003 SO IEEE Journal of Oceanic Engineering SN 0364-9059 PU IEEE VL 28 IS 1 UT 000181871700008 BP 78 EP 89 DI 10.1109/JOE.2002.808205 ID 708 ER EF