National Key Laboratory of Electromagnetic Environment;
China Research Institute of Radio Wave Propagation;
Beijing 102206;
People's Republic of China;
EISCAT;
NO-9027 Ramfjordbotn;
Norway;
UiT;
The Arctic University of Norway;
Tromso;
Norway;
EISCAT Scientific Association;
Kiruna;
Sweden;
ionospheric heating; fifth harmonic; parameter instability; altitude; intensity;