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| Titel |
Validate Mapping of Internal Lunar Magnetic Field |
| VerfasserIn |
M. C. Berguig, M. Hamoudi, J.L LeMouël, Y. Cohen |
| Konferenz |
EGU General Assembly 2012
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 14 (2012) |
| Datensatznummer |
250066941
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| Zusammenfassung |
| In this work we present a global mapping of vector lunar magnetic field based on new method
of separation of internal and external fields using inversion. The magnetic measurements
collected during the lifetime of Lunar Prospector (LP) extended mission during 1999 were
strongly disturbed by the solar wind, a period which coincided with a maximum of the 23
cycle activity. The multi scale wavelength external fields were analyzed using spherical
harmonic transform. The external field determined by inversion was then removed from each
magnetic field component for each half orbit. To map the vector magnetic crustal
anomalies, all LP magnetometer data collected at low altitudes in the three different lunar
environments: (1) geomagnetic tail (2) solar wind (3) geomagnetic sheath, were
processed using this new approach. The results obtained using these selection criteria
allow us to get a global coverage of the lunar surface by the vector magnetic field at
variable spacecraft low altitudes. To validate our mapping we have developed and
applied a method based on properties of potential fields functions. This method
can be used to determine both horizontal North and East components using only
vertical component. The validate lunar internal magnetic measurements obtained at
variable spacecraft altitudes was then continued to a common altitude of 30 km using
non linear inverse methods. This mapping confirm firstly the nature of the crustal
sources of lunar magnetic field and clearly shows that the strongest concentrations
of anomalies are associated with of high albedo and/or located antipodal to large
young basins (Orientale, Serenitatis, Imbrium, and Crisium) of age about 3.9 Ga. |
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