Schulz Leonard, Heinisch Philip, Richter Ingo
Institute for Geophysics und Extraterrestrial Physics, Technische Universität Braunschweig, 38106 Braunschweig, Germany.
Sensors (Basel). 2019 Apr 18;19(8):1850. doi: 10.3390/s19081850.
Magnetometers based on the anisotropic magnetoresistive effect are used in many applications for orientation determination, by measuring the magnetic field of the Earth. As sensors of this type are commercial, off-the-shelf components, manufacturers provide limited information on their measurement performance. Therefore, we present a (to date) unprecedented comprehensive calibration study on three state-of-the-art digital anisotropic magnetoresistance magnetometers, to precisely determine various performance parameters and stability across different sensors of the same model. With the evaluation of sensitivity, noise, offset, and orientation determination, as well as considering dependencies on temperature and frequency, the performance of each sensor can be improved significantly, enabling their implementation in demanding fields of application (such as in satellites). Different measurement and calibration techniques, specifically aimed at the characteristics of the examined magnetometers, were utilized, using a sophisticated magnetic laboratory that has served as a calibration facility for several interplanetary space missions. Our study allows operators to decide whether to consider anisotropic magnetoresitance magnetometers for their application and, more importantly, to be able to (at least partially) skip a time-intensive and complicated calibration by using the sensor parameters given in this paper. To that end, the most promising sensor is recommended. The sensor examination suggests a good comparability of different sensors of the same model, and shows the importance of noise regarding the sensor performance with a noise floor up to 124 nT/Hz at 1 Hz. Additionally, depending on the sensor model, the sensitivity is 14 nT at best, and the attitude determination error can be reduced to about 0.3° with the given calibration.
基于各向异性磁阻效应的磁力计在许多应用中用于通过测量地球磁场来确定方向。由于这类传感器是现成的商用部件，制造商提供的关于其测量性能的信息有限。因此，我们对三款最先进的数字各向异性磁阻磁力计进行了一项（迄今为止）前所未有的全面校准研究，以精确确定同一型号不同传感器的各种性能参数和稳定性。通过评估灵敏度、噪声、偏移和方向确定，并考虑对温度和频率的依赖性，每个传感器的性能都能得到显著提升，从而使其能够应用于要求苛刻的领域（如卫星领域）。我们利用了专门针对所研究磁力计特性的不同测量和校准技术，使用了一个先进的磁实验室，该实验室曾作为多个行星际空间任务的校准设施。我们的研究使操作人员能够决定是否在其应用中考虑使用各向异性磁阻磁力计，更重要的是，能够（至少部分地）通过使用本文给出的传感器参数跳过耗时且复杂的校准过程。为此，推荐了最有前景的传感器。传感器测试表明同一型号不同传感器具有良好的可比性，并显示出噪声对传感器性能的重要性，在1Hz时本底噪声高达124nT/Hz。此外，根据传感器型号，灵敏度最高为14nT，通过给定的校准，姿态确定误差可降至约0.3°。
