地磁场模型在海洋磁测资料处理中的应用研究

地磁日变改正是海洋磁测资料处理过程中的一个重要环节。本文利用地磁场综合模型与IGRF模型联合计算了西太平洋某调查工区的地磁日变数据，对比分析了相同位置的海洋地磁日变站观测数据。使用两种不同类型的地磁日变数据，分别对该测区中15条测线进行了磁测数据处理，并对这些测线及其56个交叉点进行了误差分析。研究结果认为：①当用计算数据做海洋磁测的处理时，其交叉点内符合精度在调差前基本满足海洋地质规范的要求，在调差后完全符合海洋地质规范的要求，但使用计算数据的精度低于实测数据。②磁静时，计算日变曲线和实测日变曲线拟合程度高；磁扰时，两者幅值差异较大，磁扰越强相关系数越小。磁情指数K＞4时的模型计算数据，建议谨慎使用或不使用。

Application of geomagnetic field model to marine magnetic data processing

The correction of geomagnetic diurnal variation is an important step for marine magnetic data processing. In this paper, the geomagnetic diurnal variation data of a survey area in the western Pacific Ocean was calculated using the integrated model and the IGRF model, and the results were analyzed by comparing with the observation data from the same marine geomagnetic diurnal variation stations. Both of the two kinds of data were used to process the magnetic data for the 15 survey lines in the survey area, and error analyses are made for all the survey lines and their 56 intersections. The results suggest that: (1) When the calculated data is used for the processing of marine magnetic survey data, the accuracy of the intersection points basically meets the requirements of the specifications for marine geological survey before the adjustment, and completely meets the requirements of the specifications for marine geological survey after the adjustment, but the accuracy of the calculated data is lower than the measured data. (2) The calculated diurnal variation curve had higher fitting degree with the measured in magnetostatic condition, while the amplitude difference between them is larger in the case of magnetic disturbance, and correlation coefficient decreased with the enhancement of magnetic disturbance. The model calculated data of K＞4 must be used with caution or never be used.