The magnetometer instrument MPO-MAG on-board the Mercury Planetary Orbiter (MPO) of the BepiColombo mission en-route to Mercury is introduced, with its instrument design, its calibration and scientific targets. The instrument is comprised of two tri-axial fluxgate magnetometers mounted on a 2.9 m boom and are 0.8 m apart. They monitor the magnetic field with up to 128 Hz in a \(\pm 2048\) nT range. The MPO will be injected into an initial \(480 \times 1500\) km polar orbit (2.3 h orbital period). At Mercury, we will map the planetary magnetic field and determine the dynamo generated field and constrain the secular variation. In this paper, we also discuss the effect of the instrument calibration on the ability to improve the knowledge on the internal field. Furthermore, the study of induced magnetic fields and field-aligned currents will help to constrain the interior structure in concert with other geophysical instruments. The orbit is also well-suited to study dynamical phenomena at the Hermean magnetopause and magnetospheric cusps. Together with its sister instrument Mio-MGF on-board the second satellite of the BepiColombo mission, the magnetometers at Mercury will study the reaction of the highly dynamic magnetosphere to changes in the solar wind. In the extreme case, the solar wind might even collapse the entire dayside magnetosphere. During cruise, MPO-MAG will contribute to studies of solar wind turbulence and transient phenomena.

介绍了BepiColombo任务到水星途中的水星行星轨道飞行器（MPO）上的磁力计MPO-MAG，并介绍了其仪器设计，校准和科学目标。该仪器由两个三轴磁通门磁力计组成，它们安装在2.9 m的动臂上，相距0.8 m。它们在\（\ pm 2048 \）  nT范围内以高达128 Hz的频率监视磁场。MPO将注入到初始\（480 \ times 1500 \）中 km极轨道（轨道周期2.3 h）。在水星，我们将绘制行星磁场的图，并确定发电机产生的磁场并限制长期变化。在本文中，我们还将讨论仪器校准对提高内部领域知识的能力的影响。此外，对感应磁场和场对准电流的研究将有助于与其他地球物理仪器协同约束内部结构。该轨道也非常适合研究Hermean磁更年期和磁层尖端的动力学现象。BepiColombo任务的第二颗卫星上的姊妹仪器Mio-MGF与水星上的磁力计一起将研究高动态磁层对太阳风变化的反应。在极端的情况下，太阳风甚至可能使整个白天的磁层崩溃。在巡航期间，MPO-MAG将有助于研究太阳风的湍流和瞬态现象。