ZOND

ZondTEM2D software is designed for two-dimensional    of   Transient ElectroMagnetic(TEM) and frequency sounding for several observation systems  ground and airborne. Comfortable interface and wide possibilities of data presentation allow to solve given geological problem with maximum effectiveness. While developing software special attention was payed to comfort and simplicity of its use, variety of visualization features and account of a priori data.

TEM sounding –  the methods of time domain electroprospecting  based on studying of field attenuation of vortical currents (transients) arising in electroconducting section at sharp curent off. The primary field is generated by transmission of rectangular impulses passing in not grounded loop or grounded line.  At  current off in the  source, measured voltage in receiver not instantly fall to zero but decreases gradually. It is connected to, that at the moment of current off  in conducting areas the secondary currents are induced. At the first moment of time it concentrated in near surface areas and then flow to more deep layers, fading with distance  from the source.  A physical basis of impulse electroprospecting application is contrast of electric conductivity and polarizability of rocks and ores in natural stratification. Depth of penetration of the non-stationary electromagnetic field in the earth is defined by time.  Transients are studied at the moment of current off   by  induction receivers, usually loops or small multicoil receivers.

Depending on the interpreter’s choice, software  gives different  variants   of data interpretation algorithms. Comfortable control system allows to choose from the great number of equivalents results that will appear to be the best in geophysical and geological point of view. Conception of multi-station  interpretation is basis of the ZondTEM2D software. Consequently, profile line data is considered as a reflection of geological section. It’s mean  that  multi-station data of profile line is whole, and not set of  separated curves.

ZondTEM2D allows to work with some types of  TEM acquisition systems. The program supports  traditional systems(coincident loops, in loop, VMD). Electromagnetic fields and/or their time’s derivatives can be used. Because of equivalence of inverse geophysical problems, quality of the obtained results strongly depends on the amount of used a priori data. In ZondTEM2d there is possibility of weight setting(Error gates) for measurements, fixing and limiting of different parameters, using of a priori model as reference in inversion. If the values of some section parameters are known exactly (a priori or on interpretation results), their fixing is possible before the beginning of automatic interpretation. The fixed parameters do not change during the process of inversion. Fixing of parameters is the method for  hard regularization of inversion process. The robust schemas of noise estimation are realized in the program.