地磁传感器文章，包括EMS地磁传感器、地磁导航技术及其应用、基于磁传感器MMC212的电子指南针、基于地磁原理的计转数传感器技术研究、水平定向钻进随钻姿态测量及误差补偿-Geomagnetic sensor article, including EMS magnetic sensors, magnetic navigation technology and its applications, based on magnetic sensor MMC212 electronic compass, magnetic principle based on total number of sensor technology transfer, horizontal directional drilling and drilling attitude measurement error compensation