TWO METHODS FOR MEASURING HF BAND NOISE

Two methods of measuring HF band noise are presented. The first method allows you to extract information about station interference from data on ionospheric radiosounding using linear-frequency-modulated signals – thus, the characteristics of both the signal and interference can be measured simultaneously; the informativeness of the existing ionospheric sounding method increases; however, in this case, reception is carried out in a specific radiosounding mode, which somewhat limits the possibilities of measuring noises, for example, measuring their absolute values. If only interference characteristics are needed, then it is advisable to use the second technique, which operates in the mode of a conventional "classical" radio reception. The second method is a universal, flexible method for measuring panoramas of the spectrum of noises of various types. Its flexibility lies in the possibility of wide variation of the parameters of interference measurements, including processing the stored measurement data after the experiment finishes, which allows you to use the same data for research with different purposes; the second technique can be combined with ionospheric sounding. The described methods are implemented as part of hardware and software complexes of various designs for ionospheric sounding. A technique for estimating the background noise level based on a panorama of the interference spectrum is also given. In the future, it is possible to implement an algorithm for panoramic measurement of interference in all kinds of ranges wider than a decameter one (but including it). It is proposed to do this on the basis of Software Defined Radio technology.