Analysis on Ground Clutter Mitigation Using IIR Filter and Frequency Domain Filters for C-Band Phased Array Weather Radar

The presence of “ground clutter” in the echo signal is one of the factors limiting the performance of weather radar systems. Ground clutter occurs when the radar beam is reflected by objects on the ground such as buildings, trees, or mountains. Clutter removing process is necessary to produce the accurate estimation of the three parameters (reflectivity factor (Z), mean velocity (V), and spectrum width (W)) for weather conditions like rain rates and direction, and level of weather targets. In this paper, ground clutter mitigation is done by using IIR elliptic filter in time domain, and fixed width and variable width filters in frequency domain, and then the filtering effect of these filters are analyzed and compared. We use real time-series rain data collected by C-band phased array weather radar from Beijing Institute of Radio Measurement (BIRM) and MATLAB software for simulation. From the simulation results, we found that the frequency domain filters give better performance than IIR filter for the ground clutter suppression on the C-band phased array weather radar signal.