Correction of Three Sensors in a Magnetic Field Gradiometer

Abstract

A magnetic sensor array is usually used for weak magnetic target detection. This paper presents a vector second-order gradiometer that is arranged in a vertical structure. The measurement accuracy of the gradiometer is affected by the error of each three-axis magnetometer (TAM) and the misalignment error between TAMs. By analyzing the error mechanism of the magnetic gradiometer test system, the corresponding error model for the correction of the gradient of the component is established. The error parameters of the gradiometer were estimated by the proposed method, and the gradient error of the magnetic field and the component gradient error of the magnetic field were corrected. After correction, the gradiometer is used to localize the magnetic target. Simulation results illustrate that the localization error of magnetic targets is reduced by two orders. Thus, this proposed correction method can effectively improve the locating performance of gradiometer.