海洋音響学会誌
Online ISSN : 1881-6819
Print ISSN : 0916-5835
ISSN-L : 0916-5835
31 巻 , 1 号
選択された号の論文の3件中1~3を表示しています
  • 坂田 雅雄, 浅田 昭
    2004 年 31 巻 1 号 p. 20-27
    発行日: 2004/01/01
    公開日: 2011/08/16
    ジャーナル フリー
    The bathymetry data obtained by multi-beam echo sounder is widely used and the amount is getting larger these days. But most of the existing systems to manage those data are made for common usage. So these systems cannot efficiently meet the demands varying by users who need more detailed bathymetry map for example. In this paper, first we suggest new data management system which improve these points. Next, two kinds of methods to correct errors of the bathymetry data are shown as functional components of new data management system. One is ray tracing in Earth ellipsoid and another is correction of error caused by horizontal acceleration in motion sensor. It was proved that the result of the new calculation method in ray tracing revises 5m of depth errors at a depth of about 5000m. And the error correction of the motion sensor after depth sounding was proved effective but needs more investigation.
  • 巻 俊宏, 浅田 昭
    2004 年 31 巻 1 号 p. 28-38
    発行日: 2004/01/01
    公開日: 2011/08/16
    ジャーナル フリー
    Noises of multi-beam echo sounding cause wrong bathymetry data. In this paper we discuss two improved methods of data processing to reduce noises.
    (1) Time rigid motion compensation
    Ship motion (rolling, pitching, heaving) affects the location of each footprint. We improved the timing of ship motion used in compensation. We applied new method to real data, and we managed to get more precise bathymetry data than the old one.
    (2) Noise filtering using 3D angle of incidence
    There is a strong relationship between echo intensity and angle of incidence. Usually, 2D angle of incidence on a plane of projected fan beam is used for noise filtering. However, 2D angle of incidence isn't correct if the bottom is a slope. We introduced a new method to calculate 3D angle of incidence, and applied it to real data.
  • 2004 年 31 巻 1 号 p. 62
    発行日: 2004年
    公開日: 2011/03/02
    ジャーナル フリー
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