Research Publications

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End date: 2009Subject: search.filters.subject.Bathymetry

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    Use of swath data in realtime navigation by pattern recognition
    (Marine Geodesy, 1989) Prabaharan, N.; Sivakholundu, K. M.
    A new method is proposed with the aim of reducing dead reckoning error (DRE) during multibeam echosounding survey in deep ocean. Bathymetric data is used in this method to estimate DRE in position fixing. This method can be activated at any desired interval to check the DRE accumulation in addition to available external navigation systems. A pattern recognition algorithm is developed to quantify the shift in position of a selected bathymetric feature that has been observed already once. This difference is used to correct the position fixing and navigation data
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    Quantification of changes in seabed topography with special reference to Hansthal Creek, Gulf of Kachchh, India.
    (Journal of costal research, 1993-01) Pattanshetti, S.S.; Chauhan, Onkar.; Sivakholundu, K. M.
    Variations in the bathymetry in macrotidal Hansthal Creek between 1984 and 1950 along 14 closely spaced lines, are used to quantify the volumetric changes in seabed topography in terms of erosion/accretion. Two surfaces from the bathymetric data of 1984 and 1950 have been modelled. The profile wise comparison along the transects indicates a dynamic deformation due to distinct alteration in the shoreline and a shift in the channel course. The shoreline has retreated 650 and 450 m on the northern and southern banks respectively. The studies suggest scouring of horizontally deposited fine sediments (clays deposited in an antecedent depositional phase) in the Hansthal Creek due to existing dynamic equilibrium among (a) influence of physiography in amplifying the tidal range, (b) increased efflux due to contribution through inter-creek water movements, and (c) high magnitude currents. Magnitude of erosion in the creeks, particularly on the flanks, is much more than in the axial channel. The degree of the erosion reduces from the Hansthal Creek mouth to inland (area in the close vicinity of Little Gulf of Kachchh). During the last 34 years about 71.5 x 10 super(6) m super(3) from this creek during the course of the present study. Offshoreward movement of scoured sediments and their redeposition in the outer gulf as a fill in the paleo-channel is observed.