Passive HF Doppler Radar for Oblique-Incidence Ionospheric Sounding

A multi-path multi-frequency passive HF Doppler radar for oblique-incidence sounding the ionosphere, that has been produced in collaboration between researchers at the Harbin Engineering University and V. N. Karazin Kharkiv National University, is briefly described. An original software package has been designed, and the implemented autoregressive spectrum analysis gives a root-mean-square Doppler line error of 0.02 Hz and 7.5-s time resolution. The radar has been tested over the course of several months in an ionospheric dynamical process monitoring mode.