Development, evaluation & application of a geomagnetic reference field model for attitude determination of small satellites
Development, evaluation & application of a geomagnetic reference field model for attitude determination of small satellites
The subject of this thesis is the development, evaluation and application of a new model of the geomagnetic field for the purpose of attitude determination for near-earth spacecraft. Although high accuracy magnetometers have been included in numerous missions, the accuracy in attitude determination has been moderate. The reason for this is the inaccuracy of the models used as the reference to the acquired measurements. The most widely used model is the International Geomagnetic Reference Field (IGRF).
The first important limitation of this model is the wide coverage it provides for all latitudes and longitudes. The second main limitation of the IGRF is that one of its components, the most dynamic, cannot be used onboard a satellite as it dependents on Dst, an index evaluated on earth observations and impractical to upload to a satellite. This part describes the effect of the magnetospheric ring current.
To overcome these limitations two solutions are proposed. Firstly the inaccuracy due to wide coverage was treated by performing the exact opposite operation, the segmentation of the field in different parts. Seven different segments were investigated and a different model was developed for each one. The second limitation, arising from the Dst, was treated by the development of a magnetic activity index by measurements on board the spacecraft, in real time. This index was first evaluated for its consistency by comparison to the original Dst index. Then 16 different models were developed, each one for a different level of disturbance and a different condition of use.
The last part investigates the accuracy that can be achieved in an attitude determination system by the use of these models.
University of Southampton
Michalareas, George
9bdf9fc6-004e-47eb-955e-33f762c741ce
2003
Michalareas, George
9bdf9fc6-004e-47eb-955e-33f762c741ce
Michalareas, George
(2003)
Development, evaluation & application of a geomagnetic reference field model for attitude determination of small satellites.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
The subject of this thesis is the development, evaluation and application of a new model of the geomagnetic field for the purpose of attitude determination for near-earth spacecraft. Although high accuracy magnetometers have been included in numerous missions, the accuracy in attitude determination has been moderate. The reason for this is the inaccuracy of the models used as the reference to the acquired measurements. The most widely used model is the International Geomagnetic Reference Field (IGRF).
The first important limitation of this model is the wide coverage it provides for all latitudes and longitudes. The second main limitation of the IGRF is that one of its components, the most dynamic, cannot be used onboard a satellite as it dependents on Dst, an index evaluated on earth observations and impractical to upload to a satellite. This part describes the effect of the magnetospheric ring current.
To overcome these limitations two solutions are proposed. Firstly the inaccuracy due to wide coverage was treated by performing the exact opposite operation, the segmentation of the field in different parts. Seven different segments were investigated and a different model was developed for each one. The second limitation, arising from the Dst, was treated by the development of a magnetic activity index by measurements on board the spacecraft, in real time. This index was first evaluated for its consistency by comparison to the original Dst index. Then 16 different models were developed, each one for a different level of disturbance and a different condition of use.
The last part investigates the accuracy that can be achieved in an attitude determination system by the use of these models.
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Published date: 2003
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Local EPrints ID: 465716
URI: http://eprints.soton.ac.uk/id/eprint/465716
PURE UUID: add6c304-6e5d-4d81-a353-99b127928394
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Date deposited: 05 Jul 2022 02:44
Last modified: 16 Mar 2024 20:20
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Author:
George Michalareas
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