EMD-Based Intermittent and Ground Clutter Removal in Radar Windprofilers

An empirical mode decomposition (EMD)-based intermittent and ground clutter removal algorithm for radar windprofilers is proposed. Intrinsic mode functions (IMFs) affected with intermittent clutter are identified and are separated into amplitude-modulated (AM) and frequency-modulated (FM) parts. The FM part is multiplied with the envelope of the nonamplitude-modulated signal derived from the original amplitude-modulated IMF to nullify the effect of intermittent clutter. The IMFs corresponding to ground clutter are identified from the maximum entropy spectral analysis (MESA) and are rejected prior to signal reconstruction in ground clutter removal. The proposed algorithm is applied on the radar returns of 205 MHz windprofiler at Advanced Centre for Atmospheric Radar Research (ACARR) of Cochin University of Science and Technology (CUSAT), Kochi, Kerala, India ( 10.04^{\circ} \text{N} , 76.33^{\circ} \text{E} ). The windprofiler signals corrupted with flight and helicopter echoes are retrieved and the ground clutter signatures which were not removed with existing ground clutter removal methods are removed with the proposed algorithm.