In the pre-war years, in the laboratories of the Department of Geophysical Exploration Methods of LOLGI, the development of new methods and new techniques for electrical prospecting using low and high frequency currents was carried out. A number of new electrical prospecting methods have been developed: a method for measuring anomalous fields at high frequencies, a method for measuring fields out of phase with the generator field, electrical profiling on alternating current with compensation for the normal field, etc. All of them are based on measuring only anomalous parts of the field, which leads to greater sensitivity of the methods and their extraordinary portability. At the same time, the technology and methodology of already existing electrical prospecting methods were developed and, for example, for the intensity method, equipment was designed that makes this modernized method completely different from the old method. Below are some results of some of the extensive work carried out (see article).
The question of the maximum depth at which electrical exploration can detect well-conducting ore bodies has attracted the attention of geophysicists since the very beginning of the development of geophysical methods. There are a number of statements about the depth of a number of electrical exploration methods using direct and low-frequency alternating current, sometimes supported by relevant data, and sometimes simply unfounded. However, comparing these data with each other and hence comparing the depth of different methods and choosing the deepest ones is difficult due to the heterogeneity of the conditions under which experimental data are obtained by different authors. This task is extremely important, since the direction of further scientific research in this area depends on its correct solution and even now, without developing new methods, the achievement of the maximum possible depths.
