Ionospheric sounding network and data in China - Wu Jian; Jiao Peinan; Xiao Zuo; Wan Weixing; Liu Ruiyuan; Zhao Zhengyu (2000 5th International Symposium on Antennas, Propagation, and EM Theory. ISAPE 2000 (IEEE Cat. No.00EX417), Antennas, Propagation and EM Theory, 2000. Proceedings. ISAPE 2000. 5th International Symposium on, Antennas, propagation and EM theory, 2000)