Observation of the electron density fluctuation in the E-layer with the S-310-2 and K-9M-55 rockets

The precise observation of the electron density fluctuation in the E-layer was performed with S-310-2 rocket on August 30, 1975. The more thorough observation program (with K-9M-55) is being considered to elucidate the dynamics of the E-layer. This report describes the outline of the measuring system together with its scheduled improvements and the results of the observation with S-310-2 rocket. As for the measuring system, brief description is given to the Langmuir probe, electron probe, and noise probe. The observed electron density and temperature distributions in both ascent and descent conditions are presented as the functions of altitude. The distribution of the relative amplitude of the observed electron density fluctuation is also presented. The frequency analysis of the density fluctuation at the altitude of 98 km was also made, and the reason of the spectrum peak at about 10 Hz is discussed. In the observation program scheduled to be performed with K-9M-55 rocket, the simultaneous measurement of electric field and current is expected. The outline of the improvement of the measuring system for the program is also briefly explained. (Aoki, K.)