Анотація:
The modernization of the KLAUDIA radiotelescope, used for the detection of the Earth ionosphere's secondary radiation at 40 kHz±200 Hz waves, is presented in the paper. In particular, the scope of the Very Low Frequency receiver's modernization and the construction of the high frequency grounding module is briefly discussed. The most typical features of the radio radiation of the Earth's ionosphere at 40 kHz frequency waves are presented and discussed in detail in the second part of the paper.