Exploring planetary magnetic environments using magnetically unclean spacecraft: a systems approach to VEX MAG data analysis

摘要

In situ measurements of the magnetic field are vital to the study of manyfundamental problems in planetary research. Therefore the magnetometerexperiment is a key element of the payload of Venus Express. In addition tothe interaction of the solar wind with Venus, these measurements are crucialfor the study of atmospheric escape and detection of lightning. However, themethodology for the magnetic field measurements had to be different to thetraditional approach, because Venus Express is not a magnetically cleanspacecraft. A technique based on two-point simultaneous measurements of themagnetic field and systems identification software is used to separate thenatural magnetic field from the spacecraft generated interference. In thispaper an overview of the techniques developed to separate these two fieldtypes and the results achieved for 1 Hz Venus Express data are presented.Previous publications suggest that the resulting Venus Express cleaned datais of comparable quality to measurements made from onboard magneticallyclean spacecraft (Zhang et al., 2008a, b; Slavin et al., 2009).