高精度新方法测量计算船舶磁场分布

将高精度质子磁探仪和位场变换理论用于测量计算船舶磁场，以研究其在海洋中的分布。由质子磁探仪实测海面上１０ｍ处磁场的模（船的磁场与地磁场矢量的和的绝对值），用位场变换理论计算出船的磁场三个分量在水面和水下的分布；并采用一系列有效措施，提高计算速度和结果的精度。将该方法和磁球理论严格解比较，在ｚ＝０面上误差小于０．１％，在ｚ＝－２０ｍ面上误差小于１％；还给出船的磁场强度在船的纵横向的分布曲线和平面立体

NEW HIGH PRECISION METHOD TO MEASURE AND COMPUTE MAGNETIC FIELD OF SHIP

The single component magnetometer now used in measuring a ship's magneticfield has poor precision and reliability. High precision proton magnetometers canonly be used to measure the modul of magnetic intensity. In this paper the theoryof magnetic potential field transformation is. introduced to calculate the magneticfield of ships. |T| the absolute value of the vector sum, a ship's magnetic intensityH and terrestrial magnetic field intensity T0, is measured by using a proton mag-netometer under sea surface lom. is taken to be approximatelythe projection of H in the direction of T0. The distribution of the three componentsof the magnetic intensity of a ship under the sea surface lom was inferred and thenits distribution under the sea surface was deduced by means of the Green Ftinctionmethod. A 5 000 ton sliip was used to carry out practical measurement with awooden boat.Some effective techniques were used in data processing to shortencomputing time and improve accuracy. This method is.compatible with magneticsphere theory.The error is less than 0.1 % on z= 0 and less than 1% on z =-20m.The distribution curve of the magnetic field intensity and it's three components inthe longitudinal and transverse directions of the ship and the isodynamic line andthree-dimension chart of the magnetic intensity of the ship are given.