A survey of equatorial magnetospheric wave activity between 5 and 8 R(sub E)

We report the results of a survey of ELV/VLF wave activity in the frequency range from 100 Hz to 5 kHz observed by the SCATHA satellite near the magnetic equator between 5 and 8 R sub E. The typical wave environment in this region is required to assess the role of each type of wave in transport processes, such as the pitch-angle diffusion of electrons, occurring in the outer magnetosphere. Hiss, discrete whistler-mode emissions, and electron cyclotron harmonic waves occur within the frequency range of the SCATHA VLF receiver. Hiss is predominantly observed between noon and dusk where the satellite frequently enters the plasmasphere. Discrete whistler-mode emissions occur over 60 percent of the time between 0300 and 1200 LT. A surprising result of the survey is the absence of activity in the local time sector from 18 to 21 h. No wave activity above the receiver noise level, 5 x 10 to the minus 7th power V/m-Hz1/2, was detected during 50 percent of the broadband data acquisitions in this region.