| 摘要 |
PURPOSE:To reduce an error in position measurement due to the influence of a spherical wave by improving the structure of the receiving element of a hydrophone and adding the 4th receiving element symmetrically about a coordinate origin. CONSTITUTION:The receiving element 4 is added symmetrically about the coordinate origin 0. There is almost no error in position measurement as to a calculation result based upon a calculation expression and a measurement of short distance because receiving elements are arrayed symmetrically, attaining great reduction. Namely, the photodetecting elements #1-#4 are arranged symmetrically, but may be arrayed in a corss shape so that the elements #1 and #4 are on the X axis and elements #2 and #3 are on the Y axis. Thus, the structue of receiving elements of the hydrophone is made symmetric about the coordinate origin to reduce position measurement errors due to the influence of spherical wave greatly, thereby performing practical and accurate operation efficiently. |
