Measurement of electron density profile in the lower ionosphere during nighttime by rocket observations of MF and VLF radio waves

Measurements are made on the magnetic field strength of MF and VLF radio st ations by rocket observations during nighttime, along with measurements mad e on the Langmuir probe (dc probe) current and Doppler observations of ME I n the E layer, we can observe the standing wave of the VLF magnetic field s trength, and also the ordinary and extraordinary components of ME In order to make the theoretical values by the full-wave calculation coincide with t hese observed values with reference to the de probe currents,, we adjust th e electron density and the distribution of the electron collision frequency with altitude. By these methods, the electron density of the E layer is es timated from the bottom to the top, and we find the existence of multiple w eak Es layers. By MF Doppler observation, we successfully estimate the elec tron density of the upper E layer, and can estimate the effective electron collision frequency near 110 km in altitude from the strength of the upward component of the extraordinary wave. (C) 1999 Scripta Technica.