基于最小二乘的地磁场测量误差补偿技术研究

地磁导航中获取地磁场的精确测量值是进行地磁匹配导航的前提和基础。论文针对实际地磁测量中磁力仪易受环境磁场干扰带来的影响补偿效果的问题，首先分析了软磁误差以及硬磁误差对磁场测量的影响效果，建立了地磁测量误差的参数化模型。采用ANSYS仿真软件，通过3对内径不同的亥姆霍兹线圈产生了3个方向的匀强磁场，从而实现了对地磁场的模拟。在此基础上，将磁力仪和干扰源建到仿真模型中，通过360度旋转磁力仪分别得到了有干扰和无干扰时的三维磁场值，然后采用最小二乘算法对模型参数进行了估计，最终实现了对磁场测量误差的补偿。仿真结果表明，该方法简单易行，简化了参数的求解过程，具有较高的误差补偿能力，地磁测量误差可以从20 000多纳特减少到几个纳特。

Research on Error Compensation in Geomagnetic Field Measurement Based on Least Squares

The accurate geomagnetic field value is a prerequisite and foundation for the geomagnetic navigation. To solve this problem caused by magnetometer in actual magnetic field measurement influenced by environmental magnetic field, the influence of hard iron and soft iron errors on magnetic measurement is analyzed and the parameterized geomagnetic measurement compensation model is constructed firstly. The geomagnetic field is simulated by using three pairs of Helmholtz coils to generate uniform magnetic field with the software of ANSYS. By setting the different parameters of interference source and rotating the magnetometers in 360 degrees in the simulation model, the three dimensional magnetic field values with and without interference are got. Those parameters of the model are estimated using least squares based algorithm and geomagnetic measurement errors are calibrated. The simulation results show that this compensation method is simple, and easy to use, and has higher error compensation ability, and geomagnetic measurement errors can be reduced from 20000nT to several nanoteslas.