A harmonic analysis of lunar topography

Bills, B. G.; Ferrari, A. J.

doi:10.1016/0019-1035(77)90036-7

Cited by 63 publications

(30 citation statements)

References 21 publications

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“…Recent approaches in determining the lunar figure parameters use a spherical harmonic representation of the lunar topography. In an early study, Bills and Ferrari (1977) calculated the axes of a triaxial lunar ellipsoid using a spherical harmonic analysis of lunar topography to degree 12 from Earth based and orbital observations (a, b, and c triaxial ellipsoid lunar axes are 1738. 43, 1737.50, 1736.66 km long, respectively, and the mean radius is 1737:53 e 0:03 km).…”

Section: Night Thoughts By LI Baimentioning

confidence: 99%

New parameters of geometrically best fitting lunar figures

İ̇z¹

2009

Journal of Applied Geodesy

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Abstract. The parameters of various lunar figures are of interest to the scientific community working on lunar exploration. In this study, the size of the geometrically best fitting triaxial and rotational ellipsoids, and spheres, are estimated using the method of condition equations with common unknown parameters from the coordinates of 271,610 control points of the newly available lunar control, ULCN 2005. In the first set of solutions, the origin of the figures is calculated with respect to the center of the mass of the Moon. Their origins are set to coincide with the lunar center of mass in the second set of solutions. The new estimates are the most up-to-date values for the triaxial and rotational ellipsoidal and spherical parameters of the lunar figures and are significantly di¤erent up to half a km as compared to the most recent solutions.

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Section: Night Thoughts By LI Baimentioning

confidence: 99%

New parameters of geometrically best fitting lunar figures

İ̇z¹

2009

Journal of Applied Geodesy

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“…The surface distribution of radioactive elements is also skewed to the front side of the Moon [Metzger et al, 1973;Lawrence et al, 2000]. An additional lunar asymmetry is that the center of mass of the Moon is offset toward the Earth from its center of figure (CM-CF) by $2 km [Kaula et al, 1972;Bills and Ferrari, 1977;Smith et al, 1997].…”

Section: Introductionmentioning

confidence: 99%

Global distribution of lunar composition: New results from Lunar Prospector

et al. 2002

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[1] Maps of thorium [Th], [FeO], the ratio of epithermal to thermal neutrons (E/T), and fast neutrons (FN) from Lunar Prospector were studied to determine their global distribution on the Moon. These distributions are compared to that of the 750 nm lunar albedo from Clementine to aid in their interpretation. All distributions were parameterized using a spherical harmonic expansion out to order l = 30. Resultant harmonic coefficients generally decrease with increasing l value as a power law in l for all five variables. The axes of all dipole components (l = 1) cluster closely about a centroid given by +14.1°latitude and 16.4°west longitude. This location is very close to the symmetry axes of their quadrupole components (l = 2), which cluster about a centroid given by +24.6°latitude and 25.1°west longitude. Both centroids are near the center of a suggested Procellarum basin, given by Whitaker [1981] at +23°latitude and 15°west longitude. This suggestion is strengthened by a sharp decrease of the intensities of all three variables at $50°from the centroids, which is close to the boundary of the putative Procellarum basin. The coincidence of the global concentration of heat-producing elements (through [Th]) and mare deposits on the lunar surface (through [FeO], [T/E], and [FN]) with the circular outline of a putative Procellarum basin suggests that the events that were responsible for producing Oceanus Procellarum (perhaps a single giant impact) must figure importantly in shaping the global distribution of surface composition. A second, apparently older circular structure having its center near À5°latitude and 65°east longitude and a radius of 50°is also hinted at in the data.

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“…Beyond f30" latitude and the lunar far-side these data are very sparse or non existent (Sjogren, 1986;Bills and Ferrari, 1977). Nevertheless, a harmonic analysis has been applied.…”

Section: Introductionmentioning

confidence: 99%

“…Nevertheless, a harmonic analysis has been applied. Spherical harmonics up to 12th degree and order for topography have been obtained (Bills and Ferrari, 1977). The lunar global gravity field has been fitted to two models: by the harmonics through degree and order 5 and by a sixteenth-degree harmonic series (Bills and Ferrari, 1980).…”

Section: Introductionmentioning

confidence: 99%