High frequency radar clutter power for mixed ionosphere-ocean propagation

Ionospheric clutter is one of the main sources of interference affecting the performance of high frequency surface wave radar (HFSWR). One component of this arises from a portion of the transmitted radar signal which is reflected from the ionosphere to the ocean surface, from whence it is backscattered to the receiving antennas. The influence of the ionospheric reflection can be accounted for by a so-called ionosphere reflection coefficient (IRC). This paper presents three ionospheric spectral models which may be used to determine clutter power within reasonable limitations.