FIELD: radio engineering instruments for passive ranging to electromagnetic sources, in particular, meteorology and aviation for operative detection of distance to thunderstorm activity under effective range of 300-1800 km. SUBSTANCE: electromagnetic signal of lightning is received by vertical electric antenna, is amplified, filtered by wide-band filter and converted by analog-to-digital converter. Resulted signal is checked against each of N preset scales Ln (n=1,..., n) of distance to lightning. Goal of invention is achieved by N-time parallel processing of this signal and comparison of output signals with respect to their level. Distance to lightning is defined as distance corresponding to maximal output signal. EFFECT: increased effective range, increased precision of distance measuring. 5 dwg
