000196033 001__ 196033 000196033 003__ CZ-ZdVUG 000196033 005__ 20201109113822.0 000196033 041__ $$aeng 000196033 040__ $$aABC039$$bcze 000196033 1001_ $$aHolota, Petr 000196033 24510 $$aGalerkin’s Matrix for Neumann’s Problem in the Exterior of an Oblate Ellipsoid of Revolution: Gravity Potential Approximation by Buried Masses 000196033 300__ $$a34 stran 000196033 5203_ $$aThe paper is motivated by the role of boundary value problems in Earth’s gravity field studies. The discussion focuses on Neumann’s problem formulated for the exterior of an oblate ellipsoid of revolution as this is considered a basis for an iteration solution of the linear gravimetric boundary value problem in the determination of the disturbing potential. The approach follows the concept of the weak solution and Galerkin’s approximations. The solution of the problem is approximated by linear combinations of basis functions with scalar coefficients. The construction of Galerkin’s matrix for basis functions generated by elementary potentials (point masses) is discussed. Ellipsoidal harmonics are used as a natural tool and the elementary potentials are expressed by means of series of ellipsoidal harmonics. The problem, however, is the summation of the series that represent the entries of Galerkin’s matrix. It is difficult to reduce the number of summation indices since in the ellipsoidal case there is no analogue to the addition theorem known for spherical harmonics. Therefore, the series representation of the entries is analyzed. Hypergeometric functions and series are used. Moreover, within some approximations the entries are split into parts. Some of the resulting series may be summed relatively easily, apart from technical tricks. For the remaining series the summation was converted to elliptic integrals. The approach made it possible to deduce a closed (though approximate) form representation of the entries in Galerkin’s matrix. The result rests on concepts and methods of mathematical analysis. In the paper it is confronted with a direct numerical approach applied for the implementation of Legendre’s functions. The computation of the entries is more demanding in this case, but conceptually it avoids approximations. Some specific features associated with function bases generated by elementary potentials in case of the ellipsoidal solution domain are illustrated and discussed. 000196033 655_4 $$ačlánek v odborném časopise 000196033 7001_ $$aNesvadba, Otakar 000196033 7730_ $$92019$$d2019$$g63. (1), s.1-34$$tStudia Geophysica et Geodaetica$$x0039-3169 000196033 8564_ $$uhttps://link.springer.com/article/10.1007/s11200-017-1083-x 000196033 85642 $$uhttps://www.rvvi.cz/riv?s=rozsirene-vyhledavani&ss=detail&n=0&h=RIV%2F00025615%3A_____%2F19%3AN0000003%21RIV19-GA0-00025615 000196033 910__ $$aABC039 000196033 980__ $$aclanky_vugtk 000196033 985__ $$aholota 000196033 985__ $$ariv 000196033 985__ $$autvar24 000196033 985__ $$anesvadba