METHOD FOR UNDERWATER SCANNING OF AN OBJECT AND TARGET FOR UNDERWATER SCANNING OF AN OBJECT

摘要

The invention relates to a method for improving the positioning accuracy of the scanning of an underwater object, in which method equipping the object (10) to be scanned with at least one floating target (32), which includes both a part (33) above the surface (12) of the water and a part (33.1) below the surface, determining the position data of the target (32) on the basis of the part (33) of the target (32) above the surface (12) of the water, scanning the object (10) to be scanned from under the surface (12) of the water in order to create measurement observations, detecting the target (32) from the said measurement observations under the surface (12) of the water, aligning the position data of the target (32) from the measurement observations with the detected target (32) in order to improve the positioning accuracy of the scanning, determining the target's (32) attitude data time- dependently during the scanning in order to determine the position data of the part (33.1) of the target (32) below the water surface (12) on the basis of the part (33) of the target (32) above the water surface (12), correcting the alignment of the initial position data of the part (33.1) of the target (32) below the water surface (12) with the measurement observations on the basis of the said attitude data. The invention also relates to a corresponding arrangement for the scanning of an object (10) taking place under the water surface (12).