Geoinformatika 2018; 1(65) : 48-53

SOLUTION OF NOT CORRECT INVERSE PROBLEMS FOR MAGNETIC SURVEYS OF LARGE SCALE

T.L. Mikheeva, E.P. Lapina, N.V. Panchenkoi

Institute of Geophysics, National Academy of Science of Ukraine, 32 Palladin Ave., Kiev 03680, Ukraine, e-mail: mtat@ukr.net, Lapina-Lena@ukr.net, panchenkonv@ukr.net

Purpose. To study the possibility of using an automated software complex for interpretation of gravitational and magnetic fields for the realization of a quantitative interpretation of practical data. The proposed approximation design provides the interpreter with ample opportunities for modeling objects of complex shape, determining the geometric and physical parameters of magnetically disturbing sources.

Design/methodology/approach. The computer experiment was carried out using algorithms for automated selection. The software complex makes it possible to obtain multivariate solutions and easily realize the principle of sequential complication and refinement of the model in the process of solving modeling problems. Several classes of bodies, fundamental forms for interpretation (a single-connected contour, a stellar body) were used as an approximating construction and were used as approximating cells for describing geological objects in interpreting observed anomalies.

Findings. The proposed approximation design allows us to conveniently parametrize perturbing sources with a complex distribution of physical properties, to implement a selection strategy with sequential complication of the model, moving from the use of simple approximating cells to more complex ones. In the Second Ukrainian Antarctic Marine Antarctic Expedition in Bransfield Bay, when developing methodological issues of modeling anomalous magnetic objects, the developed technology of approximating them with complex contours was used.

Practical value /implications. When interpreting magnetometric data, it is expedient to solve concrete practical problems using the method of sequential complication of the model of the object under study. At the initial stages of modeling, it is possible to introduce a rough approximation of individual objects with polygonal contours of small dimension, at subsequent stages to introduce the approximation of objects with complex contours with a small number of parameters. The performed calculations provide strong reasons to state that the high-intensity anomalies at the beginning of the 0704 line are due to magnetically disturbing sources with higher magnetization values.

Keywords: inverse problem, approximate construction, magnetic field, geological object, intensity of magnetization,
cylindrical cell with polygonal section, star body, interpretation.

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References:

1. Andreev V. Y. Modelyrovanye heolohycheskykh obrazovanyi metodamy prostranstvennoi hravymetryy. M.: Nedra, 1992, 224 p. [in Russian].
2. Balk P.Y., Dolhal A.S. Obratnye zadachy hravymetryy kak zadachy yzvlechenyia dostovernoi ynformatsyy v uslovyiakh neopredelennosty. Fyzyka Zemly. 2012, no 5, pp. 85 — 101. [in Russian].
3. Blokh Yu.Y. Kolychestvennaia ynterpretatsyia hravytatsyonnykh y mahnytnykh anomalyi. M.: MHHA,1998, 88 p. [in Russian].
4. Bulakh E.H., Zeihelman M.S., Korchahyn Y.N. Avtomatyzyrovannyi podbor hravytatsyonnykh y mahnytnykh anomalyi: prohrammno-alhorytmycheskoe obespechenye y metodycheskye rekomendatsyy. K., 1986, 235 p. (Preprynt. Ynstytut heofyzyky AN USSR. Dep. v VYNYTY 08.12.86, N 8363-V86). [in Russian].
5. Bulakh E.H., Mykheeva T.L. Reshenye priamykh i obratnykh zadach hravymetryy v klasse zvezdnykh tel. Dokl. NAN Ukrayny. 1993, no. 7, pp. 81 — 85. [in Russian].