Ionospheric clutter extraction in HFSWR based on range-doppler spectral image processing

The detection capability of the high frequency surface wave radar (HFSWR) is severely limited due to the strong interference from the sea/ground and the ionospheric clutter, etc. Since the ionospheric clutter occupies a lot of range and Doppler cells with strong echo energy in the range-Doppler (R-D) spectrum, the target is submerged in the clutter region, which seriously affects the target detection capability of HFSWR. In this paper, an ionospheric clutter region extraction method is proposed based on the morphological analysis of the ionospheric clutter region distribution characteristics in the R-D spectrum image. Furthermore, to overcome the weakening of the target echo strength induced by the ionospheric clutter, the peak detection method is applied to improve the target detection ability of HFSWR. Finally, the proposed method is validated by the field data of HFSWR, which shows that the new detection method can effectively identify the ionospheric clutter region on the R-D spectral image with higher target detection precision comparing with the traditional image processing method combining with the constant false alarm rate (CFAR) target detection results.