Use this URL to cite or link to this record in EThOS: http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.656741
Title: Advances in spacecraft magnetic cleanliness verifcation and magnetometer zero offset determination in anticipation of the solar orbiter mission
Author: Pudney, Maxsim
ISNI:       0000 0004 5349 3267
Awarding Body: Imperial College London
Current Institution: Imperial College London
Date of Award: 2014
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Abstract:
The Solar Orbiter mission aims to study the Sun by linking what the spacecraft visibly detects on the Sun's surface with the measurements it makes in-situ in the solar wind, which will advance our knowledge of how the Sun controls the inner heliosphere. The spacecraft has strict magnetic cleanliness requirements that demand deviation from standard testing, analysis and data correction practices. We present advances made towards the detection of magnetometer zero offsets and the verification of unit magnetic field emissions in anticipation of the Solar Orbiter mission. We demonstrate an improvement to the detection of magnetometer zero offsets through the automatic calculation of a key parameter vital to the removal of the spacecraft field from measured data. The existing technique uses pre-existing rotations in the solar wind to calculate the magnetometer zero offsets. Our improvement uses the measured solar wind data to automatically calculate the important minimum compressional standard deviation (MCS) parameter, demonstrating an improvement in the offset calculation probability of up to 10% at aphelion and 5% at perihelion. We also suggest an improvement to the extrapolation of source emission measurements made close to equipment under test (EUT), in order to verify field emissions against strict magnetic cleanliness requirements. We propose the use of magnetic field scaling that follows an inverse square law close to the EUT and an inverse cube law beyond a chosen break distance 3 times the scale size of the EUT. Due to the importance of the 1-100 kHz range to the search coil instrument on Solar Orbiter, we study a potential improvement to the shielding effectiveness of test facilities over this frequency range. We test a small prototype design using thin high permeability layers that demonstrates shielding by a factor of 90 at 8 kHz, however when scaled up to test facility size we find that aluminium shielding is more effective.
Supervisor: Carr, Chris; Schwartz, Steve Sponsor: EADS Astrium ; Science and Technology Facilities Council
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID: uk.bl.ethos.656741  DOI: Not available
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