三分量磁通门梯度仪校准算法研究

针对三轴磁通门传感器非正交、灵敏度不一致、零偏以及构成梯度仪的两个磁通门传感器位置不一致引起的测量误差问题,建立了误差模型;基于地磁矢量模值短时不变原理,采用线性化最小二乘算法进行一个磁通门传感器参数的辨识;基于校准后三分量差值F范数最小原理,采用多元线性回归的方法进行另一个磁通门传感器参数以及两个磁通门传感器相对位置关系参数的辨识。实验结果表明,该方法能够将两个磁通门中最大总场误差从1 194.4 n T降低到30.0 n T,将三分量梯度仪最大输出误差从529.1 n T降低到13.4 n T,有效地改善了梯度仪性能。

Study on the calibration method for tri axis fluxgate gradiometer

Aiming at the measurement errors caused by non orthogonality, inconsistent sensitivity, zero offset of the tri axis fluxgate sensor and the position misalignment of two fluxgate sensors composed of the gradiometer, the error model is established in this paper. Based on the invariance principle of total geomagnetic field vector modulus in a short time, the parameter identification of the first fluxgate sensor is performed with linear least squares algorithm; based on the principle of the minimum F norm of the 3 component difference after calibration, the parameter identification of the second fluxgate sensor and the relative position between two fluxgate sensors are conducted with the multiple linear regression method. The experiment results show that the proposed method can reduce the maximum total magnetic field error of two fluxgate magnetometers from 1 194.4 nT to 30.0 nT, and the maximum output error of the three component gradiometer from 529.1 nT to 13.4 nT. The performance of the gradiometer is effectively improved.