摘要：From the direction finding (DF) observations based on the measurement of wave arrival time differences among three spaced points around Syowa Station (geomagnetic lat. -70.0°), the arrival direction of narrow-band auroral hiss was examined. It is found that the ionospheric exit from which the narrow-band auroral hiss comes out is usually located in the lower latitude side than the position of quiet auroral arcs. These results demonstrate that the propagation path of auroral hiss is deviated from the geomagnetic field lines along which auroral particles precipitate. Therefore, it is concluded that the waves propagate downwards to the ionosphere in a non-ducted mode. Comparing the location of the ionospheric exit of auroral hiss with the ratio of 8kHz hiss intensity at Syowa to that at Mizuho, it is estimated that the loss rate of auroral hiss is, on the average, 2-3 dB/100km with respect to the horizontal direction.
