Bathymetric survey athydrothermal site byL-array Interferometric sonarmountedonAUV-r2D4

Autonomous Underwater Vehicle isexpected for transmitter. LA-IFSsystem isnewly designed toovercome its stability asplatform ofmanysensors. AUV-r2D4 that can weaknesses thatconventional IFS systems(6)(7) actundertheseauptoadepth of4,000m wasbuilt forthe containing onetransmitter andtwohydrophones foreach purpose offinding andsurveying hydrothermal deposit and side have. Ournewsystem arranged three hydrophones in already withmanyadvanced sensors someinvestigations have L-array shapeenabled us to removeambiguity of beenperformed. Forr2D4wehavebeendeveloping new differential phase measurament. Andthus wecould settwo bathymetric sonarthatarranges threehydrophones in ofthree hydrophones withlonger distance (approximately L-array shape beside bothside's transmitters usually usedas 16times oftransmitted wavelength) ledtoseafloor depth sidescansonar. Thesesystems calculating theangles of measurement withhigher resolution (1). Thedevelopment arrival ofbackscatter signals fromdifferential phase calledofr2D4started in2002andwe already haveperformed interferometric orbathymetric sidescanconsist oftwo several experiments andsurveys withr2D4.Inthis paper hydrophones andonetransmitter. Ournewsystem arrangedwe willintroduce theresults ofseafloor mapping with three hydrophones atL-array shape (LA-IFS) enabled usto LA-IFSat Central IndianRidgeexperimented on resolve unwrapping problem andledustomakehigherDecember 2006. This areahasbeenreported anddiscoverd resolution bathymetric chart. LA-IFShasadvantages for somehydrothermal plumes andwecould attain indication AUV because ofitssimple design andenergy savingofhydrohermal activities. performance. Andasbathymeter itslongrange anddense Theconstitution ofthis paper isindicated below. Inthis swathbathymetry, of coursebackscattering, provideschapter thepurpose andsummeryofthisarticle was effective alternative toAUVequipments. We haveperformedshowed. Andatsecond chapter wewill explain thesystem someinvestigation withr2D4. Inthis paper weintroduce the ofLA-IFSanditsprinciple ofhowtomeasure thedepth. results ofLA-IFS's bathymetric surveying atCentral Indian Andatthird chapter we willpresent aprocess ofdata Ridge onDecember 2006.