The Cluster Magnetic Field Investigation: overview of in-flight performance and initial results

TLDR

Let's collect: Background: one sentence: "The magnetic field is a key constituent of the plasma in and around the magnetosphere, and it plays an active role in all physical processes that define the structure and dynamics of magnetospheric phenomena on all scales." Purpose: we have two Purpose lines: first: "The accurate measurement of the magnetic field along the orbits of the four Cluster spacecraft is a primary objective of the mission." second: part of Purpose, Mechanism line: "We present an overview of the instrumentation used to measure the magnetic field on the four Cluster spacecraft and an overview the performance of the operational modes used in flight." So combine: Purpose: measurement objective and overview of instrumentation and performance. Need single sentence. Mechanism: we have Mechanism lines: from Purpose, Mechanism line: same as above. Also separate Mechanism line: "Further data analysis is expected to bring an even more accurate determination of the calibration parameters." Also Mechanism, Other line: "We also describe the data processing flow and the implementation of data distribution to other Cluster investigations and to the scientific community in general." So Mechanism: instrumentation, operational modes, calibration, data processing flow, distribution. Findings: multiple Findings lines: first: "With the four-point measurements on Cluster, it has become possible to study the three-dimensional aspects of space plasma phenomena on scales commeasurable with the size of the spacecraft constellation, and to distinguish temporal and spatial dependences of small-scale processes." second: "We also report on the results of the preliminary in-orbit calibration of the magnetometers; these results show that all components of the magnetic field are measured with an accuracy approaching 0.1 nT." third: "Several examples of the capabilities of the investigation are presented from the commissioning phase of the mission, and from the different regions visited by the spacecraft to date: the tail current sheet, the dusk side magnetopause and magnetosheath, the bow shock and the cusp." So Findings: 3D measurement capability, calibration accuracy, examples of capabilities.

Abstract

Abstract. The accurate measurement of the magnetic field along the orbits of the four Cluster spacecraft is a primary objective of the mission. The magnetic field is a key constituent of the plasma in and around the magnetosphere, and it plays an active role in all physical processes that define the structure and dynamics of magnetospheric phenomena on all scales. With the four-point measurements on Cluster, it has become possible to study the three-dimensional aspects of space plasma phenomena on scales commeasurable with the size of the spacecraft constellation, and to distinguish temporal and spatial dependences of small-scale processes. We present an overview of the instrumentation used to measure the magnetic field on the four Cluster spacecraft and an overview the performance of the operational modes used in flight. We also report on the results of the preliminary in-orbit calibration of the magnetometers; these results show that all components of the magnetic field are measured with an accuracy approaching 0.1 nT. Further data analysis is expected to bring an even more accurate determination of the calibration parameters. Several examples of the capabilities of the investigation are presented from the commissioning phase of the mission, and from the different regions visited by the spacecraft to date: the tail current sheet, the dusk side magnetopause and magnetosheath, the bow shock and the cusp. We also describe the data processing flow and the implementation of data distribution to other Cluster investigations and to the scientific community in general.Key words. Interplanetary physics (instruments and techniques) – magnetospheric physics (magnetospheric configuration and dynamics) – space plasma physics (shock waves)