Two-point direction finding of magnetospheric VLF emissions exit regions

Twenty-four-hour direction-finding measurements made on 19 February 1999 at the mid-latitude stations separated 150 km apart in latitude have shown that VLF emissions can be released from various ionospheric regions at each station, although from the same azimuthal directions. In this case low-frequency chorus and high-frequency hiss arrived mainly from the dierent azimuth sectors. The exit points of hiss from the ionosphere are usually located in a southern or southeastern direction from the station zenith and for chorus, in the zenith or in the northern direction.