FN Archimer Export Format
PT J
TI Analysis of seafloor backscatter strength dependence on the survey azimuth using multibeam echosounder data
BT 
AF LURTON, Xavier
   ELEFTHERAKIS, Dimitrios
   AUGUSTIN, Jean-Marie
AS 1:1;2:1;3:1;
FF 1:PDG-DFO-NSE-ASTI;2:PDG-DFO-NSE-ASTI;3:PDG-DFO-NSE-ASTI;
C1 Inst Francais Rech Exploitat Mer Ifremer, IMN NSE ASTI, Underwater Acoust Lab, CS 10070, F-29280 Plouzane, France.
C2 IFREMER, FRANCE
SI BREST
SE PDG-DFO-NSE-ASTI
IN WOS Ifremer jusqu'en 2018
IF 1.471
TC 24
UR https://archimer.ifremer.fr/doc/00386/49782/50326.pdf
LA English
DT Article
CR ETAL2040-02
   REM2040-02
BO Thalia
DE ;Azimuth dependence;Seafloor backscatter;Multibeam echosounder;Sand ripples
AB The sediment backscatter strength measured by multibeam echosounders is a key feature for seafloor mapping either qualitative (image mosaics) or quantitative (extraction of classifying features). An important phenomenon, often underestimated, is the dependence of the backscatter level on the azimuth angle imposed by the survey line directions: strong level differences at varying azimuth can be observed in case of organized roughness of the seabed, usually caused by tide currents over sandy sediments. This paper presents a number of experimental results obtained from shallow-water cruises using a 300-kHz multibeam echosounder and specially dedicated to the study of this azimuthal effect, with a specific configuration of the survey strategy involving a systematic coverage of reference areas following “compass rose” patterns. The results show for some areas a very strong dependence of the backscatter level, up to about 10-dB differences at intermediate oblique angles, although the presence of these ripples cannot be observed directly—neither from the bathymetry data nor from the sonar image, due to the insufficient resolution capability of the sonar. An elementary modeling of backscattering from rippled interfaces explains and comforts these observations. The consequences of this backscatter dependence upon survey azimuth on the current strategies of backscatter data acquisition and exploitation are discussed. 
PY 2018
PD JUL
SO Marine Geophysical Research
SN 0025-3235
PU Springer
VL 39
IS 1-2
UT 000430016500013
BP 183
EP 203
DI 10.1007/s11001-017-9318-3
ID 49782
ER

EF