Design and application of the multi‐transmitting and multi‐receiving ionospheric detection network

To observe a large area of ionosphere with relatively dense observing points, we design and implement an experimental multi‐transmitting and multi‐receiving ionospheric detection network in China. Two transmitters located in Wuhan and Mile and two receivers located in Kaiyuan and Luxi are used to form the ionospheric detection network. The radio echoes of the network are reflected at the mid‐point ionosphere between the transmitter and receiver. The radio systems in the network work simultaneously and the echoes from the two transmitters can be recorded in one ionogram of a receiver. With the inversion technique, the oblique‐incidence ionogram is converted to a vertical‐incidence ionogram, and then the ionospheric parameters, such as the critical frequency and peak height of F2‐layer ( f o F2 and h m F2), as well as the electron density profile, can be obtained. The f o F2 variation recorded by the oblique‐incidence ionograms is compared with the same data of the vertical‐incidence ionosondes in Qujing and Chongqing. There is a little deviation between the observation results of the two kinds of the ionospheric detection systems. The preliminary experimental results show that the ionospheric oblique‐incidence detection network composed of several independent high‐frequency transmitters and receivers is an effective and low‐cost solution for large‐area ionospheric observation.