| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide an on-the-sea earth magnetism measuring method capable of performing magnetism measurement stably and accurately at bay inlet or coast and shallow sea area and the like. SOLUTION: The sensor 1 of magnetic meter such as a portable 'Overhauser proton magnetic meter' for ground is fixed to a boat in one by projecting from the stern of a non-magnetic material small boat (FRP boat) so that the effect of induction magnetism from an engine made of magnetic material such as iron is reduced as much as possible. Simultaneously at the front middle of the boat, a similar magnetic meter 5 fixed on a gimbal 4 to measure the earth magnetism and fluctuation difference of the earth magnetism due to rolling of the boat at every 1 second interval for example during cruising. Each of the measured values of the position of the boat, the direction of bow, water depth required in analyzing the measured results of earth magnetism and two measured values of the earth magnetism at the stern and the front of the boat are separately taken out of each measuring apparatus as digital values and recorded in real time.</p> |
