HR: 1340h
AN: T13D-0509    [Abstracts]
TI: Advanced Method of Multi-beam Data Processing to Obtain Detailed and Precise Bathymetry in Deep Sea
AU: * Yokoi, Y
EM: yokoi@ohti.co.jp
AF: Ocean High Technology Institute, Inc., 2-51-10, Honcho, Nakano-ku, Tokyo, 164-0012 Japan
AU: Ueki, T
EM: ueki@ohti.co.jp
AF: Ocean High Technology Institute, Inc., 2-51-10, Honcho, Nakano-ku, Tokyo, 164-0012 Japan
AU: Murai, M
T13D-0509 AF: Japan Hydrographic Association, 5-3-3, Tsukiji, Chuo-ku, Tokyo, 104-0045 Japan
AB: Comprehensive and detailed bathymetric data derived from the multi-beam echo sounding measurement are useful to provide evidence for establishment of the outer limits of the continental shelf beyond 200 nautical miles under article 76 of the UN Convention on the Law of the Sea such as determination of the foot of slope and 2,500m isobath._@Since the Multi-beam echo sounding data are vast in large area, efficient processing tool is necessary to deal with such vast amount of data. Existing multi-beam data processing software is insufficient as follows. Firstly, multi-beam data include spurious depth measurements (noises). Cutting noises from vast data by manual editing that is conventionally used by existing software takes very long time. Secondly, existing software use the interpolation method too much beyond necessary. Finally, filtered grid data are less reliable than original depth measurements. But existing software does not have the capability to evaluate the reliability of grid data by comparing them with original depth measurement. To reduce above insufficiencies, we developed new softwares. Those main improvements are as follows. Operating efficiency was improved by increasing automation of noise-cutting processing. The noise-cutting method is Robust Curve Surface Estimation Method that is recommended by IHO. This is one of the weighted average methods. The weight is based on residual between estimated curve surface and beam depth. Interpolated grids were less than conventional software. By considering physical spreading of each beam, more grids can be generated. Overlaying with original depth measurement on the 2-dimensional view and 3-dimensional view assessed quality of grid data. For example, it suggests that small relieves of grid are by noise or not. We will present effect of the software with practical examples of its application to the multi-beam data set obtained by marine scientific research for continental shelf outer limits in the western Pacific Ocean.
DE: 3002 Continental shelf and slope processes (4219)
DE: 3045 Seafloor morphology, geology, and geophysics
DE: 9355 Pacific Ocean
SC: Tectonophysics [T]
MN: Fall Meeting 2005