Characteristics of amplitude spectra of whistlers at frequencies below 1 kHz /the Interkosmos-5 and Interkosmos-14 satellites/

Amplitude spectra of whistlers at frequencies below 1 kHz are presented which were obtained by the Interkosmos-5 and Interkosmos-14 satellites in the upper ionosphere at heights of 400 to 500 km and 1000 km during the day and at night. Results are reported for whistlers generated by electrons, whistlers generated by protons, and whistlers that generate ELF radiation. The observational technique is briefly described, along with the method used for the digital processing of the magnetic recordings of the signals. The observed spectra are shown to be in qualitative agreement with the theoretical properties of the transmission function for ELF waves propagating through the ionosphere.