In recent strapdown airborne and shipborne gravimetry campaigns with servo accelerometers of the widely used Q-Flex type, results have been impaired by heading-dependent measurement errors. This paper shows that the effect is, in all likelihood, caused by the sensitivity of the Q-Flex type sensor to the Earth’s magnetic field. In order to assess the influence of magnetic fields on the utilised strapdown IMU of the type iMAR iNAV-RQH-1003, the IMU has been exposed to various magnetic fields of known directions and intensities in a 3-D Helmholtz coil. Based on the results, a calibration function for the vertical accelerometer is developed. At the example of five shipborne and airborne campaigns, it is outlined that under specific circumstances the precision of the gravimetry results can be strongly improved using the magnetic calibration approach: The non-adjusted RMSE at repeated lines decreased from 1.19 to 0.26 mGal at a shipborne campaign at Lake Müritz, Germany. To the knowledge of the authors, a significant influence of the Earth’s magnetic field on strapdown inertial gravimetry is demonstrated for the first time.

在最近使用广泛使用的 Q-Flex 型伺服加速度计进行的捷联机载和船载重力测量活动中，结果受到航向相关测量误差的影响。本文表明，这种影响很可能是由 Q-Flex 型传感器对地球磁场的敏感性引起的。为了评估磁场对使用的 iMAR iNAV-RQH-1003 型捷联 IMU 的影响，IMU 已暴露于 3-D 亥姆霍兹线圈中已知方向和强度的各种磁场中。基于结果，开发了垂直加速度计的校准功能。在五个舰载和机载运动的示例中，概述了在特定情况下使用磁校准方法可以大大提高重力测量结果的精度：在德国 Müritz 湖的一次船载运动中，重复生产线上未经调整的 RMSE 从 1.19 毫加仑降至 0.26 毫加仑。据作者所知，首次证明了地球磁场对捷联惯性重力测量的显着影响。