Influence of ionosphere on SCR of HF hybrid sky-surface wave radar

The HF hybrid sky-surface wave radar is a new system radar, and because of the complex characteristics of ionosphere as a propagation medium, its detection performance is widely determined by the state of ionosphere. Combined with the layout of the radar system and the character of receiving in wide beam, this paper analyzes the influence of ionosphere on the size of resolution cell and signal to clutter ratio (SCR). First of all, it analyzes and calculates the influence of ionospheric dispersion and irregularities on resolution. Then, it analyzes the calculation methods of the area of resolution cell under the condition of the bistatic radar and the wide beam, and analyzes ionospheric irregularities´ influence on the size of resolution cell. At last, according to the basic equation of HF hybrid sky-surface wave radar, it deduces the influence of ionosphere on SCR, and do the simulation with parameters of typical system and ionosphere. The simulation results show that ionospheric dispersion and irregularities affect the size of the resolution cell, reduce the SCR, which go against the detection of ship targets.