To be installed near the GPS stations provide information about the distribution of electrical conductivity within the Earth. They consist of electromagnetic field sensors (magnetometers and electrode) and a central unit acquisition, preprocessing, transmission in near-real time and data storage. The various sub-systems are battery powered, which can be recharged by solar cells. The working performance of the acquisition system can be controlled by monitoring device, which gives some parameters which characterize the operation thereof during the period that remains on. The data transmission is dependent on the premises and may be via internet and satellite.