抄録
According to the first report, not only the position of a sea bottom transponder but also the underwater acoustic velocity can be determined, if the position of sea surface transponders and the distances between the surface and bottom transponders are known. In the second report, a theoretical possibility of obtaining the position of the sea bottom transponder with accuracy of centimeter order is shown. For the purpose, estimation of the underwater acoustic velocity distribution as a part of solution is extremely important. Effects of errors in the positions of the surface transponders and the distances between the surface and bottom transponders are also obtained in detail. In the previous papers, two dimensional calculations are conducted.
In the present paper, more realistic simulations are conducted by introducing three dimensional calculations. And a new idea called MIL (Method of Incremental Layers) are developed to stabilize numerical calculations.
