"嘉庚"号船载地磁三分量数据采集、处理和分析OA

[Objective]Due to vehicle magnetic interference,difference in data transfer latency and complexities of compensation calibrations and algorithms for ship magnetism,the accuracy of the shipborne geomagnetic three-component measurement system(STCM)is limited.Unfortunately,such a limitation restricts popularization and application of STCM.[Methods]Therefore,taking advantage of the nonmagnetism above the main deck of RV TAN KAH KEE,we carry out the experiment of self-developed STCM in the northern South China Sea,and mainly summarize practical and effective ways of registration synchronization of the fluxgate sensors with POS,and calculations for total field constraint and compensation.Focusing on the difficulty of registration synchronization caused by difference in data transfer latency,we use simulated three-component data of the comprehensive error model to synchronize their registration.Likewise,focusing on the deviation of the three-component model of geomagnetic field from the real background field,we solve the magnetic compensation parameters with the total field constraint obtained by the towing measurement.[Results]In this test,the root-mean-square of over-cross differences of the compensated total fields of STCM before and after synchronization is reduced from±17.75 nT to±12.91 nT,and the root-mean-square of its difference with the total field obtained by the towing measurement is reduced to less than±20 nT.[Conclusion]Results show that registration synchronization plays a more critical role than the pure ship magnetic compensation model and its algorithm improvement do in improving STCM measurement accuracy.Although attitude data are not used in the total field constraint and compensation solution,their application is necessary in synchronization,three-component constraint and compensation solution.Finally,reasons for mismatch and other high-frequency interference of three-component are summarized,as well as optimization measures of suppressig for these sources.These data processing procedures can benefit the popularization and application of STCM.