TOSTER

This program is intended for MT data inversion along the profile and on the grid. The nucleus of the program is a direct one-dimensional algorithm for calculating the MT field. The parameters of inversion include entering the amplitude-phase curves for separate MT sites, their calculation errors, the geometric arrangement of sites on the profile (grid), and a priori information about the geoelectric properties of the grid being investigated.

Inversion is based on the construction and the subsequent nonlinear minimization of the general functions of discrepancies in combination with the empiricist-heuristic corrections in the course of minimization. User can assign a priori information about the geoelectric cros-section both in the form of a rigid fix of resistivities in the separate blocks, and in the form their probabilistic estimation.

Special script-language TOSTER-Script was created for the purpose of automatic inversion parameters input and their dynamic changes, and the program itself has an interpreter. Programming language capabilities allowed the creation of an algorithm for the self-taught inversion without the application of a priori information, which is being successfully used for MT data interpretation by Nord-West Ltd. A graphic user interface allows the user to examine, estimate and select results at each point of sounding with any iteration. The extended export capabilities of obtained geoelectric model include: the output of cross-sections, resistivity maps, conductivities and selection discrepancies.

TOSTER software is being successfully used by Nord-West as one of the main tools for medium geoelectric model construction. It possesses a friendly and intuitively intelligible graphic user interface. Customization of input-output file formats is possible upon request.