To accurately estimate a three-dimensional ionosphere electron density distribution using a signal from a known broadcasting station when estimating an ionosphere electron density distribution of a passage route by a signal transmitted from a satellite.
The electron density estimation device includes a first calculation section which computes an arrival azimuth and an elevation angle of radiowaves received by an array antenna, a total electron number calculation section which computes a total electron number of a passage route of a satellite signal, a three-dimensional electron density estimation space setting section 36 which sets a three-dimensional space for estimating an electron density and divides the three-dimensional space into two or more areas, an electron density estimation section 38 which estimates an electron density per area, a hop number calculation section 39 which computes a hop number of radiowaves received by the array antenna, a determination section 41 which determines an estimation result by the electron density estimation section to be right when the difference between the distance from the array antenna to a transmission source computed based on the hop number and an actual distance is no longer than a predetermined threshold, and a correction section 43 which corrects the electron density at a propagation route of radiowaves depending on a determination result of the determination section 41.
Iwa Saki Kokuni
Masakazu Ito
Shunichi Takahashi
Toshio Takamatsu