Research on Backscattering of Sky Wave from Sea Surface

Abstract

For a long period, the sky-wave over-the-horizon radar (OTHR) has difficulty in detecting ship under the background of sea clutter, and it is difficult to apply the existing sea clutter model established in surface wave propagation mode to the sky-wave OTHR sea clutter suppression. Therefore, the difference between surface wave and sky wave propagation mode is analyzed firstly, then the scope of grazing angle about sky wave beam is calculated, finally the backscattering coefficients of sky wave from sea surface are derived by perturbation method and the backscattering mechanisms of sky wave from sea surface are analyzed. Results show that the mechanisms observe Bragg scattering mechanism. The backscattering coefficients of sky wave from sea surface which are given in this paper for the first time are significant for sky-wave OTHR sea clutter suppression.